38 Memorias de (& Sociedad Oientítica 



be modified and perfeeted in a tKousand ways, and several 

 may be brought into connection. It consists o£ a damp cham- 

 ber bounded by walls o£ cement and gypsum, or a paste o£ 

 carbonate o£ lead and linseed oil (skin) with e£Eerent capilla- 

 ry tubes (excretory apparatus). Between tbe two glasses and 

 the two partitions tkere are big drops of Bñtschli's cytoplasm 

 or "artificial protoplasm'' and water. In the middle stands a 

 digestive apparatus formed o£ tkin caontchouc or o£ a snake's 

 lung; two tubes o£ glass serve to keep it open at tbe ends, 

 and it is made narrower in the middle ; it receives food (pep- 

 tone, water, and some sugar soIutions ) through one end and 

 expels it througg the other. For this purpose the mouth is co- 

 vered a£ter filHng the cavity. The whole is afterwards hea- 

 ted by means of a small oil-íamp, and then eooled or dried, 

 whilst the currents and the osmotic phenomena, the deposits, 

 concretions, etc., are observed. The internal currents and mo- 

 vements are stimulated or paralysed according to the condi- 

 tious mimicking those called vital. As respiration cannot be 

 imitated, the heat afforded by oxidations may be replaced by 

 that furnished by the small oil-lamp ; after all it is exactly 

 the same thing. The two glasses being diffieult to unite they 

 may be replaced by Vierordt's glass-box or haematochro- 

 meter. 



México, Abdl 30, 1899. 



