164 'SUMMARY OF CURRENT RESEARCHES RELATING TO 



AVhen the food contains carbohydrates, these are subjected to the action 

 of an enzyme secreted by the protoplasm, and are converted into simple 

 sugars. These are conveyed by osmosis through the protoplasm, and are 

 no doubt in part used up in cell-metabolism. If in excess of immediate 

 needs, they are stored up in the refracting-bodies as glycogen. The 

 author is disposed to lay considerable emphasis on the investing mem- 

 brane of these bodies, as an important agent in the process of conversion 

 of the sugar into glycogen. If food becomes scarce, then the zymogen 

 in the vicinity of the investment gives rise to an enzyme which permeates 

 the membrane, converts the glycogen into sugar, and so permits the 

 process of osmosis to recommence. The origin of the refracting-bodies 

 is somewhat obscure, but it is probable that they originate during periods 

 of abundant food, and that the investing membrane is the first part to 

 appear. In a note, the author points out how admirably Pelomyxa 

 is adapted for the experiments on the chemical physiology of simple 

 organisms. 



Experiments on BinTugia.* — Dr. Eugene Penard has succeeded in 

 several cases in separating the intact nucleus from the cytoplasm of 

 Difflugia, and in three cases in accomplishing this without other ma- 

 terial injury to the organism. Separated nuclei preserve a healthy 

 appearance for from 9-24 hours after being liberated, but they ultimately 

 die, apparently of inanition. On the other hand, the non-nucleated 

 specimens lived and moved about for several days after the removal of 

 their nuclei, apparently unaffected by the operation, and in the three 

 cases, when finally killed for purposes of examination, were seen to 

 consist of apparently normal protoplasm. Food-taking was hot observed 

 in non-nucleated animals, but perfectly intact forms can remain without 

 food for weeks without injury, and there seems no reason to doubt that 

 the mutilated specimens could ingest food-particles. 



Deep-Sea Rhizopods in Clyde Area.f — F. G. Pearcey remarks on 

 the interest of finding deep-sea forms in the Clyde area, aud records 

 the following new species : — two Astrorhizidee — Storthosphxra depressa 

 and Bathysiphon minuta, and one of the Lituolidse Hippocrepina oblonga. 



Infusoria of Lake Geneva.^ — Jean Eoux gives some brief notes 

 on the results of lake-dredging for Ciliata. He has obtained about 

 eighty species, about four times as many as those previously recorded. 

 The majority of the species are littoral, and occur most abundantly 

 where the bottom is covered by plants. Pelagic forms are exceedingly 

 rare, and almost all belong to the Peritricha. They occur attached 

 usually to Fragilaria or Botryococcus, both abundant forms. Up to a 

 depth of 25-30 metres the bottom has a fairly abundant fauna. At 

 this depth there occur both fixed forms and free Hypotricha aad Holo- 

 tricha as well as others. No observations were made at depths greater 

 than 30 metres. 



Structure and Development of Colpodella pugnax.§ — Prof. P. A. 

 Dangeard finds that this Infusorian occurs not unfrequently as a para- 



* Rev. Suisse Zool., viii. (1900) pp. 477-90. 



t Communications Millport Station, i. (1900) pp. 37-42 (2 pis.). 



X Rev. Suisse Zool., viii. ( 1900) pp. 459-65. 



§ Le Botaniste (Dangeard), vii. (1900) pp. 5-29 (1 pi.). 



