302 



PROCEEDINGS OF THE ACADEMY OF 



[May, 



lar (figs. 5, 6, 11).^ This structure was observed iu the fresh cell 

 long before finding a fixation which preserves it. Subsequently, 



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m 



■1/b 



Gr 



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Fio;. 6. — Cell from median portion of the "mid-gut " of Oniscus nsel- 

 lus, fixed in 1 per cent, platiuic chloride 15 parts, 1 per cent, osmic 

 acid 4 parts, sixteen hours after feeding, and stained in iron hfematoxy- 

 lin. Drawn with camera lucida, X 600. The alveolar structure of the 

 cytoplasm is preserved. Tlie shaded portion below the nucleus indi- 

 cates an artifact produced by unilateral penetration of the killing fluid 

 (see page 306). The alternation of fibres and alveoles is shown. Alb. 

 Gr., albumose granules ; Int., iutima ; 3Tus., muscle. 



by examining very carefully with high powers sections from an in- 



^It is possible that even this structure is due to "sub-mortem " 

 changes, as Hardy indicates. I have made many attempts to discover 

 tlie alveolar structure in the gut of very young, transparent animals 

 while still living ; but without success. Nevertheless it would be pre- 

 mature to conclude from Hardy's studies on artificially prepared colloids 

 alone that there is no formed structure in the living protoplasm. Should 

 tliis be shown m time, wc should then necessarily conclude that the co- 

 agulation incident to the "sub-mortem" changes is practically instan- 

 taneous, since the structure shown in Fig. 5, can be seen as soon as the 

 preparation can be made (within one-half minute from the removal of 

 the intestine). Pending further studies on this subject, I refrain from 

 calling this alveolar structure, living. 



It should be said that this paper was in press before Hardy's very sug- 

 gestive one on "Structure of Cell Protoplasm " was seen. 



