APIOCYSTIS. 



[ 54 ] 



APOTHECIUM. 



matter {g), probably an early stage of Bad. 

 termo, for it is always found with and 

 prior to it in decomposing liquids, in addi- 

 tion to the molecular granules found in all 

 animal liquids. 



This fungus appears to arise in the same 

 manner as other analogous fungi, as those in 

 kept organic liquids, in urine, &c.; the spores 

 are probably always floating in the air and 

 dropping from it upon all the exposed parts 

 of the body ; and wherever they find a pro- 

 per nidus, there they grow. In diseases 

 accompamdng or preceding aphtha, the re- 

 generation of the oral e]3ithelium is probably 

 to a great extent checked, the secretion of 

 the saliva also, which would wash away 

 these organisms ; why they occur so fre- 

 quently in infants, is probably owing to the 

 saccharine nature of the diet, wdiich is espe- 

 cially favom*able to their development. See 



OlDIUM. 



BiBL. C. Robin, Histoire Naturelle des 

 Vegetaux Parasites, 2nd ed., Paris, 1853, 

 p. 488, where many other w^orks are men- 

 tioned. 



APIOCYSTIS, Nageh.— A genus of Pal- 

 mellacese ( Confervoid Algae) . Aquatic plants 

 parasitical upon Confervae, consisting of 

 pear-shaped or clavate vesicles, from 1-50" 

 to 1-20'' high, and about half as thick, at- 

 tached by the narrow extremity, and con- 

 taining numerous green primordial cells 

 about l-2500"tol-3500'' in diameter. Young 

 sacs contain regularly 2, 4, 8, 16, 32, &c., 

 and in large ones the number amounts to 

 300 to 1600. At first they lie nregularly in 

 the cavity, afterwards they lie upon the wall 

 in one or more layers ; sometimes they are 

 attached to the wall in groups of eight. At 

 a certain stage, the piimordial cells become 

 again fi-ee in the cavity, move actively, and 

 finally escape by the rupture of the sac, 

 swarm as biciliated zoospores for a time, 

 then settle down and germinate. 



A. Brauniana and the doubtful species 

 A. linearis represent this genus; they have 

 not been recorded in this country, having 

 been discovered at Ziirich by Nageli. 



BiBL. Nageli, Einzelligen Algen, p. ^T . 

 t. 2, A. figs. 1 and 2. 



APIS, L. — A genus of Hymenopterous 

 insects. 



A. mellifica, the honey-bee, presents some 

 interesting points of structure. 



The proboscis (PI. 2Q. fig. 25) agrees 

 essentially with that of Anthojjhora. The 

 " tongue " (lalnum*) is a very beautiful and 

 favourite microscopic object ; its minute 



structure requires a higher power than that 

 used in making our sketch, to render distinct 

 the elegant transverse ridges or folds and 

 the terminal hairy lobe. 



The legs are peculiarly formed for the 

 special purpose of collecting and carrying 

 the pollen of flowers. The tibiae of the 

 hind legs are dilated, smooth on the outside 

 in the neuter or w orking bees, and hollowed 

 into a shining plate (PI. 2/. fig. 4 b), whilst 

 the basal joint of the tarsi is hooked at its 

 outer superior angle and dilated into an 

 oblong or somewhat triangular plate (PL 27. 

 fig. 4 a), which is furnished wdth transverse 

 row^s of hairs, forming pollen-brushes. 



BiBL. Westwood, Introduction, &c.; Cur- 

 tis, Brit. Entom. 769. 



APOTHECIUM.— The name apphed to 

 the spore-frmts of the Lichens, sometimes 

 restricted to those of the open-fruited genera 

 (Gymnocarpi), the term perithecium being 

 applied to those of the closed-fruited (An- 

 giocarpi). Several special names have been 



Fig. 28. 



Fig. 29. 



Fig. 30. 



Dirina Ceratonise. 



applied to the apothecia, namely, jjelta, 

 scutella, patella, scypJius, orbiculus, lirella, 

 and verruca, indicating the forms occurring 

 in particular genera. They are shield- 

 shaped, flat, cuj)- shaped, globular, papilliform 

 bodies or linear ridges, upon the ujiper 



