INDEX AND GLOSSARY. 403 



Alkalies, tests for, 108. 



Alkaloids, tests for, 18, 111. 



Allantois, 204 (Gr. sausage-like). An oblong sac developed 

 in the embryonic life of animals near the end of the intestine, 

 and serving for temporary respiration. 



Alcyonium, 165. A genus of Coralline polyps. 



Algae, 139 (Lat. sea weeds}. The great variety in form and 

 organization shown by this class of plants render it an inter- 

 esting field of microscopic research. The families of Desmids 

 and Diatoms have been particular favorites. 



Alternation of Generations, 126. This term denotes a form 

 of reproduction in which the }?oung do not resemble the parent 

 of the animal but the grandparent. 



Alimentary canal in insects, 177. 



Amides, 184. A term used in chemistry to express a com- 

 pound ammonia, in which one, two, or three of the hydrogen 

 atoms are replaced by an acid radical. 



Ammonia. Volatile alkali. Used in preparing carmine 

 fluids, 69, 72. Test for ammonia, 107. Used as a test, 108, 

 111, 112. The crystals of ammoniacal salts are often beautiful 

 microscopic objects. The hydrochlorate forms cubes, octahe- 

 dra, and trapezohedra, but if crystallized rapidly makes pecu- 

 liar feathery crystals. It does not polarize. Crystals of oxa- 

 late, oxalurate, and purpurate of ammonia are beautiful objects 

 for the polariscope. 



Ambulacra (Lat. ambulacrum, a place for walking). Holes 

 or avenues in the shell through which the tube feet of Echino- 

 derms are protruded. 



Amnion, 204 (Gr. amnos, a lamb). One of the fetal mem- 

 branes of the higher vertebrates. 



Amoeba, 121 (Gr. amoibos, changing). Animals of simplest 

 form, composed of a glutinous living substance or bioplasm. 



Amoeboid Cells, 121, 128. Cells with movements similar to 

 Amoeba have been found in vegetables as well as animals. See 

 Bioplasm. 



Amplifier, 26, 346. 



Amphipleura Pellucida, 56. A test diatom for high powers. 

 The valves are linear lanceolate, with a median longitudinal 

 line. No median nodule. The striae are exceedingly fine. 



