INDEX AND GLOSSARY. 405 



Annual Rings, 156. Concentric rings seen in sections of 

 Dicotyledonous stems. They probably indicate periods of foli- 

 age, and more than one may be produced in a year. 



Androspore, 152 (Gr. a male seed). A peculiar body set 

 free from a germ-cell during the development of (Edogonium, 

 and probably some other Confervacese. 



Annulus of Ferns, 155. The ring surrounding the capsule 

 which contains the spores. 



Anomalous. Irregular, contrary to rule. 



Antennae, 175 (Lat, antenna, a yard-arm). The jointed horns 

 or feelers of most Articulata. 



Anther, 157 (Gr. anthos, a flower). The case which contains 

 the pollen of a plant. 



Antheridia, 154. The so-called male organs of urn mosses 

 and similar plants. 



Antherozoids, 152. The fertilizing cells of some of the Con- 

 fervacese. Used also synonymously with Spermatozoids. 



Aphides, 126. Plant lice. Order, Hemiptera. Their pro- 

 duction is an example of the alternation of generation as well 

 as parthenogenesis, 



Aphtha, 329 (Gr. to fasten upon). Thrush, or muguet, a 

 disease of the mouth, etc., in children, or in adults towards the 

 fatal termination of chronic disease. Supposed to be the pro- 

 duct of Oidium albicans, or thrush fungus. 



Aplanatic, 26 (Gr. without deviation). Refers generally to 

 spherical aberration in lenses. 



Apothecia, 154. The shields of Lichens ; firm horny disks 

 arising from the thallus, etc., containing spores. 



Aqueous humor, 220. 



Arachnida, 338 (Gr, arachne, the spider). The class of 

 animals containing spiders, scorpions, mites, etc. 



Arachnoid Membrane, 225. A delicate cobweb-like mem- 

 brane between the pia mater and dura mater of the brain. 



Arachnoidiscus, 148. A beautiful circular Diatom. The 

 markings vary. A. Ehrenbergii is common on the Pacific 

 coast. 



Arcella, 159 (Lat. area, a chest). A genus of Rhizopods. 

 The test of the common species, A. vulgaris, has delicate 

 markings like the valves of Diatoms. 



