80 QUARTERLY CHRONICLE OF MICROSCOPICAL SCIENCE, 



which may be generally characterised as an extremely compli- 

 cated and ramified vascular cavity [schlauch) , the wall of which 

 possesses fixed cells, but no formed intercellular substance, 

 and, further, many round cells (or mucus-cells) of peculiar 

 character. This structure, which may be regarded as the 

 typical connective tissue of mollusks, is modified in other parts 

 of their organism into a more solid tissue by increase of the 

 intercellular substance and of the fixed cells, while the 

 vascular tubes acquire at the same time a distinct endothe- 

 lial lining. Flemming has never observed true fibrillse of 

 connective tissue in any of the mollusks (Prosobranchiata 

 and Lamellibranchiata) examined by him. 



VI. Muscle. — Flogel (' Schultze's Archiv,' viii, 69) de- 

 scribes the striated muscle of a mite, genus Trombidium, 

 and compares it with that of a crustacean (Cyclops), also 

 with that of a cockchafer. He agrees with Krause as to the 

 muscle-compartments or boxes, divided by transverse parti- 

 tions, but differs from him and all other observers in some 

 particulars. He worked with osmic acid, which is optically 

 very advantageous. 



VII. Nervous System. — 1. Elin "The Minute Nerves of the 

 Buccal Mucous Membrane.'' {' Schultze's Archiv,' vii, 382). 

 Elin used the gold method with tartaric acid. Found me- 

 dullated fibres, with a distinct nucleated sheath, passing into 

 non-medullated fibres with intercalated nuclei, running 

 mostly parallel to surface and united into a network in upper- 

 part of mucosa. From these very fine fibres enter papillae 

 and epithelium ; those entering epithelium have granular 

 varicosities and form an imperfect network. They are also 

 connected with cellular bodies. Those which run to upper 

 layers of epithelium return to the mucosa, looping round 

 epithelial cells. In general, his observations agree with 

 those of Klein, and also with those of Chrschtschouowicz on 

 the mucous membrane of the vagina. 



2. Jobert ('Journal de FAnatomie,' vol. vii, p. 611, 

 1870-71) discusses tlie nerves of sensation in two researches, 

 one on the tactile apparatus of the extremities of a Raccoon 

 {Procyon lotor), another on the tactile apparatus of Gaste- 

 ropoda. In the palmar surface of the digits of Procyon he 

 found the corpuscles of Meissner, not previously observed 

 except in man and the anthropoid apes, while in the deeper 

 layers were found groups of Vater's corpuscles. Nerves termi- 

 nate in both these bodies, which are very closely connected 

 with the neurilemma, of which they may, so far as their non- 

 nervous part is concerned, be regarded as a special develop- 

 ment. 



