668 GLOSSARY. 



divlduals seem to represent two species alternately reproduced, in which also 

 parthenogenesis alternates with the ordinary engendering by impregnation. 



Alula. A little wing. 



Ambulacra. (Lat. ambulacrum, an avenue or place for walking.) The perforated 

 series of plates in the shell of the sea-star or sea-urchin. 



Ambulatory. (Lat. ambulo, I walk.) An animal or a limb made for walking. 



Ammonites. An extinct genus of Mollusca, allied to the Nautilus, which in- 

 habited a chambered shell, called Ammonite from its resemblance to the horns 

 on the statues of Jupiter Ammon. 



Amorphous. (Gr. a, without ; morphe, form.) Bodies devoid of regular form. 



Ampiiipods. (Gr. ampki, on both sides ; pous, a foot.) The order of Crustacea, 

 which have feet for both walking and swimming. 



Amphistoma. (Gr. amphi ; stoma, a mouth.) The genus of suctorial parasitic 

 worms, which have pores like mouths at both ends of the body. 



Ampulla. (Lat. a bottle.) A membranous bag, shaped like a leathern bottle. 



Anaima. (Gr. a, without ; aima, blood.) The name given by Aristotle to the 

 animals which have no red blood, and which he supposed to be without blood. 



Analogue. A part or organ in one animal which has the same function as anotlicr 

 part or organ in a different animal, ^ee Homologue. 



Anastomose. (Gr. ana, through ; stoma, mouth.) When the mouths of two 

 vessels come into contact and blend together, or when two vessels unite as if 

 such kind of union had taken place. 



Androgynous. (Gr. aner, a man ; gune, a woman.) The combination of male 

 and female parts in the same individual. 



Anellata. (Lat. annellus, a little ring.) The worms in which the body seems to 

 be composed of a succession of little rings, characterised by their red blood. 



Anellide. The anglicised singular of Anellata. 



Anenterous. (Gr. a, without i^nteron, a boweh) Animals which have no in- 

 testinal canal. 



Annulated. (Lat. annulus, a ring.) When an animal or part appears to be 

 composed of a succession of rings. 



Anourous. (Gr. a, without ; oura, a tail.) Tail-less. 



Antenna. (From the Latin for yard-arm.) Applied to the jointed feelers or 

 horns upon the heads of insects and Crustacea, and sometimes to the analogous 

 parts, which are not jointed in worms and other animals. 



Anthozoa. (Gr. anthos, a flower ; zoon, an animal.) The class of Polypes, in- 

 cluding the actinia and allied species, commonly called animal-flowers. 



Antiperistaltic. (Gr. anti, against ; and peristaltic.') When the vermicular 

 contractions of a muscular tube follow each other in a direction the reverse of the 

 ordinary one. 



Antlia. ( From the Latin for pump.) Eestrictively applied to the spiral instni- 

 mcnt of the mouth of butterflies and allied insects, by which they pump up tlio 

 juices of plants. 



Aorta. (Gr. aorte, the wind-pipe ; and also the name of the great vessel spring- 

 ing from the heart, which is the trunk of the systemic arteries.) It is exclusively 

 applied in the latter s'ense in modern anatomy. 



Aphidian. Belonging to the insect called aphis, or plant-louse. 



Apical. (Lat. apex, the top of a cone.) Belonging to the pointed end of a cone- 

 shaped body. 



Ai'ODAL. (Gr. a, without ; poda, feet.) Footless ; without feet or locomotive 

 organs: fishes are so called which have no ventral fins. 



Apterous. (Gr. a, without ; pteron, a wing.) Wingless species of Insects or 

 Birds. 



Arachnida. (Gr. arachne, a spider.) Spiders, and the animals allied to them in 

 structure. 



Arborescent. (Lat. arbor, a tree.) Branched like a tree. 



Artiirodial. (Gr. arthron, a joint.) It is restricted to that form of joint in 

 which a ball is received into a shallow cup. 



Articulata. (Lat. articulus, a joint.) Animals with external jointed skeletons 

 or jointed limbs. 



