Gene-Seed

Gene-seed is the colloquial term for the material that allows for the creation of the superhuman Space Marines. Gene-seeds are artifically created bundles of tissue originally created by the Emperor for this purpose, and most commonly refer to the progenoid glands. There are 19 types of Gene-seed, each used to create one of the 19 specialized organs implanted into the body of a human warrior to create a Space Marine. As many of these implants are neural in nature, it is important to note in many of these implantations the subject must be awake, without painkillers.

Gene-seed Implants
Since the first founding, Space Marines chapters have lost the ability to make new implants, or otherwise do not have all 19 implants available to their chapter. All chapters are different in this respect, but the "purest" chapters in this respect are the Grey Knights, Ultramarines and Dark Angels. However, all chapters have the Black Carapace, as this is necessary for a marine to use his armour, and the Progenoid Glands, without which the chapter would be incapable of creating new marines.

The implantation of new gene-seed organs has over the centuries turned into a near-religious ritual, and therefore some of the organs have lost their meaning to the implanter, and because of this and the implantation turning into a ritual instead of an operation, some Marines will need further operations after the implant to fix imbalances caused by poor surgery.

Certain implants are used as plot devices, such as the use of the Sus-an Membrane in one of the Warhammer 40,000 novels by the publishing arm of Games Workshop. Used by a main character to enter suspended animation, it allowed him to survive in deep space for thousands of years, thereby tying the past to the present in the novel. Similarly, the Omophagea is used in another novel, concerning the Soul Drinkers, when a main character absorbs some of the memories of a fallen combatant, after consuming his brain matter.

Canonical material is often self-conflicting regarding the progenoid glands. Storm of Iron referred to a facility controlled by the Adeptus Mechanicus were new progenoids were being made, though whether this was an actual production facility or a storage facility was never fully explained.

Secondary Heart
This is the first and least difficult implant to install. The Secondary Heart increases blood supply and pumping capacity, and is capable of taking over entirely should the primary heart fail, and enables Marines to survive low-oxygen conditions and traumatic injury.

Ossmodula
This implant uses specially created hormones, combined with a diet high in ceramic-based chemicals, to considerably strengthen the skeleton of a Space Marine. Two years after the implantation, the Marine's skeleton will be exponentially stronger; and the rib cage will be fused into a solid mass of bulletproof interlaced bone plates.

Biscopea
Implanted into the chest cavity, this small, spherical implant bolsters muscle growth throughout the Marine's body.

Haemastamen
Implanted into a main blood vessel, the Haemastamen alters the Marine's blood composition to carry oxygen and nutrients more efficiently. It also acts as a growth control for many of the later implants.

Larraman's Organ
This organ manufactures Larraman Cells. These serve the purpose of platelets, but act faster and more effectively. When a Marine is wounded, Larraman Cells are released, attached to leukocytes. At the site of the injury, they form a skin substitute of near-instant scar tissue, effectively preventing massive blood loss and infection.

Catalepsean Node
Implanted into the back of the brain, this implant allows a marine to function in situations where sleep is impossible to safely attain. Instead, when deprived of sleep, the Catalepsean Node 'cuts in', allowing the Marine to 'switch off' sections of the brain sequentially, while remaining awake and alert (although prolonged use can be hazardous). The longest any Space Marine has ever been on active combat duty without rest is 328 hours, achieved by a squad of the Crimson Fists. This implant bears a resemblance to a theory as to how dolphins such as the Bottlenose "sleep": shutting off sections of their brain while remaining awake and alert under the functions of the other sections.

Preomnor
The Preomnor is a decontamination chamber inside the chest cavity, effectively a 'pre-stomach'. It chemically analyses ingested materials and neutralizes toxins. The Preomnor enables the Marine to eat normally inedible substances and resist poisons, and it also prevents the Marine from becoming intoxicated (unaware of his surroundings).

Omophagea
Implanted into the spinal cord, this organ is designed to absorb DNA related to experience or memory. This enables the Marine to gain information, in a survival or tactical sense, simply by eating an animal indigenous to an alien world or situation. The Marine can actually absorb vivid memories and information from deceased opponents by eating their brains. This organ may also have led to the various flesh-eating or blood drinking rituals performed by some chapters, notably the Blood Angels and their successors.

Multi-lung
The multi-lung is a 'third' lung, able to absorb oxygen from environments poor in oxygen. Breathing is accomplished through a sphincter in the trachea. A similar muscle closes the primary lungs off in toxic environments, while oxygen is absorbed by filtering out the poisonous elements in the multi-lung.

Occulobe
Implanted behind the eyes, this organ enhances a Marine's eyesight, granting him exceptional vision and the ability to see normally in low-light environments.

Lyman's Ear
This implant renders a Marine immune to dizziness and nausea (see Cochlea), greatly enhancing their combat effectiveness in zero-gravity, and enables a Marine to consciously filter out "white noise".

Sus-an Membrane
This implant allows a Marine to enter a catatonic or "suspended animation" state. It can allow a mortally wounded Space Marine to survive his injuries, and bring the metabolism to a standstill. However, specific stimulations from an external source are required to bring a suspended Space Marine back to full life. The longest recorded period of this state was Brother Silas Err of the Dark Angels for 567 years. It should be noted that Talonmaster Zso Sahaal of the Night Lords legion slept through 100 centuries after his cruiser was entombed in the Warp by the Eldar shortly after the Horus Heresy, only to be awoken late in the 41st millennium. The Imperial Fists and their successor chapters are deficient in this implant.

Melanochrome
Linked to pigment cells in skin, this allows the Marine's skin to shield him from dangerous levels of radiation and extreme temperatures along with the Mucranoid. Because of its link to pigment some chapters have no variation in skin color (the Salamanders chapter is known for its dark brown skin tone and the marines of the Death Specters chapter are albino).

Oolitic Kidney
This organ works in conjunction with the Preomnor, filtering blood to rapidly remove toxins.

Neuroglottis
This organ allows a Marine to assess a wide variety of things simply by taste. From poisons to chemicals to animals, a Marine can even track his quarry by taste alone.

Mucranoid
Altering sweat glands, this organ secretes an oily substance that coats the skin, protecting it from extreme temperatures and to some extent vacuum environments.

Betcher's Gland
Implanted into multiple locations inside a Marine's mouth, these glands transform a Marine's saliva into corrosive, blinding acid, strong enough to work through iron bars. It is not explained why this acid does not damage the mouths of Marines. The Imperial Fists and its successor Chapters are deficient in this implant. The intent of this organ is for Marines to be able to chew through virtually any material, certain Chapters, such as the Iron Snakes have the ability to spit this acid fair distances, much like spitting cobras.

Progenoid Glands
Implanted into both the neck and chest cavity, these serve to collect and cultivate the gene-seed from a Space Marine's body, and to safeguard it for the continuity of a Chapter. The neck gland matures after 5 years, while the chest gland matures after 10 years and both glands can be removed either after maturation or immediately after a marine has died in battle. The Progenoid Gland is one of the most important organs for a chapter (alongside the Black Carapace), for if a chapter were to lose the Progenoid there would be no more Space Marines.

The Black Carapace
The last and one of the most important of all the implants, this neuroreactive material is implanted directly under the skin. After a few hours, the material hardens and interlinks with the Marine's own nervous system. Points are then cut into the Carapace which allows a Marine to directly interface with his power armour. Note that a Marine needs this for his power armour, but the armour itself does not need this implant in order to function. The Sisters of Battle, for example, as well as some Inquisitors, also wear power armour. However, since they are not linked directly to their armour as a Marine would be, their power armour is markedly less efficient than that of a Space Marine.

Creating Gene-seed Implants
The gene-seed of a chapter is passed down through the Progenoid Glands, (the 18th implant) that collects and stores genetic data. There are two of these glands, one in the throat, and one in the reinforced chest cavity. This is done mainly for safe keeping, but also it gives a chance for a Chapter who has received massive losses, to possibly regenerate itself over a long period of time. They mature over a period of five to ten years, and can be harvested at any time after reaching maturity, up until a short time after death. Each gland contains the seed for one of each of the specialized organs necessary to create a Space Marine. After removal, samples are taken and cultivated to grow new organs and allowing a chapter to increase in number (although those that follow the Codex Astartes will generally avoid doing this because the Codex dictates that a Chapter must have 1000 Space Marines). Thus, a Marine's death means another will be added to the ranks, and the fallen hero lives on in some small way in each new warrior that follows in his footsteps.

In the event of a Chapter suffering disastrous losses of its gene-seed, it may become necessary for the Apothecaries of the Chapter to use test-slaves (humans, usually the condemned criminals that are turned into servitors, who are kept inside an artificial environment; alive and conscious, but unable to leave their glass case). Needless to say, this is not ideal, and is regarded as a last option. This method is also used to create the large number of gene-seed necessary for the creation of a new Chapter since no existing Chapter could spare 1000 copies of its gene-seed. However, as each chapter has to send 5% of its gene-seed away to Terra to be checked for purity, it is possible that Terra could build up a collection of gene-seed, and found new chapters that way.

(Interestingly, provided that the 5 year Progenoid gland can be reused, it would only take 10 years for 211 Marines using both the 5 year gland and the 10 year gland to become 1,000. They get 95% of seed rounded down, or 200 sets of seed in the first batch, giving 211+200=411 Marines. This 411 give a further 390 sets of seed after 5 years, with the first set replenishing the 5 year gland, and the new 200 Marines using it for the first time. together with 200 sets more coming from the 10 year gland. Taking this together, 211+200+390+200=1,001 Marines(with 43 sets of seed sent back to Terra) in 10 years by normal replacement with no losses.)