Conway smiled, although he knew that a long time would elapse before any of the trainees would be able to recognize that peculiarly Earth-human facial grimace for what it was. “Usually I have to remind some of our extraterrestrial candidates at this point that the initial letter of their classification should not be allowed to give them feelings of inferiority, because the degree of physical evolution is controlled by environmental factors and bears little relation to the level of intelligence …
Species with the prefix A, B, or C, he went on to explain, were water-breathers. On most worlds life had originated in the sea, and these beings had developed intelligence without having to leave it. D through F were warm-blooded oxygen-breathers, into which group most of the intelligent races of the Federation fell, and the G and K types were also oxygen breathing, but insectile. The Ls and Ms were light-gravity, winged beings.
Chlorine-breathing life-forms were contained in the 0 and P groups, and after these came the more exotic, the more highly evolved physically and the downright weird types. Into these categories fell the radiation-eaters, the cold-blooded or crystalline beings, and entities capable of modifying their physical structures at will. However, those beings possessing extrasensory powers sufficiently well developed to make ambulatory or manipulatory appendages unnecessary were given the prefix V regardless of their size or shape.
“There are anomalies in the system,” Conway went on, “and these must be blamed on a lack of imagination and foresight by the originators. The AACP life-form, for instance, has a vegetable metabolism. Normally the A prefix denotes a water-breather, there being nothing lower on the evolutionary scale than the piscatorial lifeforms, but the AACPs are intelligent vegetables and plant-life came before the fish.”
Conway pointed suddenly at a nurse who was spraying nutrient onto a young Hudlar at the other end of the ward, then turned toward Danalta. “Perhaps you would like to classify that life-form, Doctor.”
“I am not Danalta,” the Melfan Conway was addressing protested. Even though the process of translation tended to filter the emotional overtones from messages, the ELNT sounded displeased.
“My apologies,” Conway said, looking around for its twin, in vain. He decided that Danalta, for reasons known only to itself, had hidden behind the group of Tralthan trainees. Before he could redirect the question, one of the Tralthans answered it.
“The being you indicate is encased in a heavy-duty protective suit,” the big FGLI said, this deep modulated rumblings of its native speech reinforcing the ponderous and pedantic style of the translated words. “The only part of the being visible to me is the small area behind the visor, and this is indistinct because of reflections from the ward lighting. Since the protective suit is self-propelled, there is no evidence available as to the number and type of the locomotor appendages. But the overall size and shape of the suit together with the positioning of the four mechanical manipulators spaced around the base of the conical head section — assuming that for ergonomic reasons these mechanical extensions approximate the positions of the underlying natural limbs — leads me to state with a fair degree of certainty that the entity in question is a Kelgian of physiological classification DBLF. Glimpses of a gray, furry tegument and what appears to be one of the Kelgian visual sensors revealed, however unclearly, through the small area of the visor, supports this identification.”
“Very good, Doctor!” But before Conway could ask the Tralthan its name, the entrance lock of the ward swung open and a large, spherical vehicle mounted on caterpillar treads rolled in. The sphere was encircled equatorially by a variety of remote handling and sensory devices, and prominently displayed on the forward upper surface was the insignia of a Diagnostician. Instead, Conway pointed to the vehicle and said, “Can you classify that one?”
This time one of the Kelgians spoke first.
“Only by inference and deduction, Senior Physician,” it said as slow, regular waves rippled along its fur from nose to tail. “Plainly the vehicle is a self-powered pressure vessel which, judging by the external bracing evident on the sphere, is designed to protect the ward patients and medical staff as well as the occupant. The walking limbs, if there are any, are concealed by the pressure envelope, and I would say that the number of external handling and sensory devices is so large that it is probable the being has only a small number of natural manipulators and sensors, and operates the external devices as required. The walls of the pressure vessel are of unknown thickness, so that there is no accurate data available to me regarding the size and physical configuration of the occupant.”
The Kelgian paused for a moment and sat back on its rearmost legs, looking like a fat, furry question mark. Silvery ripples continued to move slowly along its back and flanks, while the fur of its three fellow DBLFs twitched and tufted and flattened randomly as if there were a strong wind blowing in the observation gallery.
An air of restlessness, of low-key agitation, seemed to pervade the other members of the group. The Tralthans were each raising and lowering their stumpy, elephantine feet in turn. The continuous clicking and scraping sound was the Melfans tapping their crablike legs against the floor, while the teeth of the Orligians showed whitely in their dark, furry faces. Conway hoped they were smiling.
“I am aware of two life-forms which use a pressure vessel of this kind,” the Kelgian went on. “They are utterly dissimilar in environmental requirements and physiology, and both would be considered by the more common oxygen- and chlorine-breathing species to be among the exotic categories. One is a frigid-blooded methane-breather who is most comfortable in an environment at a few degrees above absolute zero, and who evolved on the perpetually dark worlds which have been detached from their original solar systems and drift through the interstellar spaces.
“Physically they are quite small,” the Kelgian continued, “averaging one-third of the body mass of a being like myself. But during contact with other species, the highly refrigerated life-support and sensory translation systems which they are forced to wear are large and complex and require frequent power recharge …
Three of them! Conway thought. He looked around for the Tralthan who had correctly tagged the suited DBLF, and Danalta, the Melfan trainee who had identified the FROB, to observe their reactions to the very knowledgeable Kelgian — but the group was milling about so much that he could not tell who was who. Certainly he had sensed something unusual about this bunch shortly after taking charge of them at the hospital’s staff entry port.
The other life-form,” the Kelgian was saying, “inhabits a heavy-gravity, watery planet which circles very close to its parent sun. It breathes superheated steam and has a quite interesting metabolism about which I am incompletely informed. It, also, is a small life-form, and the large size of its pressure envelope is necessitated by its having to mount heaters to render the occupant comfortable, and surface insulation and refrigerators to keep the vicinity habitable by other life-forms.
“The environment of the Hudlar ward is warm with a high moisture content,” the Kelgian continued, “and some measure of the low internal temperature required by a methane-breathing SNLU would be conducted, no matter how efficient the insulation to the outer fabric of the vehicle, where condensation would be apparent. Since condensation is not present, the probability is high that the vehicle contains the high-temperature life-form, a member of which species is said to be a Diagnostician at the hospital.
“This identification is the result of deduction, guesswork, and a degree of prior knowledge, Senior Physician,” the Kelgian ended, “but I would place the entity in physiological classification TLTU.”