114 PROCEEDINGS OF THE ACADEMY OP [1884-. 



a form of parencli3^matous digestion of the food taken by the 

 animal, passing the resulting chyle into the walls of the intestine 

 by means of its pseudopodia. Now by reference to an article by 

 MetschnikofT " On Intracellular Digestion in Invertebrates " (in 

 tlie Quarterl3^ Journal of Microscopical Science for Januar}^, 1884), 

 it will be seen that such a form as Korotneff describes has never 

 been met with, and his description stands alone and anomalous, 

 both as regards the situation and size of the digestive plasmodium, 

 and as to the method of its formation, for in all cases in which 

 such structures have been found in invertebrates, they have 

 always arisen by the fusion of separate cells, not from the 

 repeated division of one cell. In a large number of series 

 of sections made by the new " ribbon " method, the speaker was 

 not only unable to find " the lumen obliterated " by the peculiar 

 structure of the wall of the intestine described by Korotneff, but 

 in a model of the visceral nucleus made after Born's " platten- 

 modillir method" the lumen of the entire intestinal canal is shown 

 to be completely tree throughout. He did, however, get sections 

 which gave pictures almost identical with those portrayed by 

 Korotneff, i. e. the lumen filled with what he describes as a large 

 nucleated granular cell, containing various food particles, and he 

 could trace this so-called " cell," not only back into " the portion 

 of the intestine lying next to the stomach," but through the 

 rectum into the cloacal chamber, and through the oesophagus 

 into the branchial sac. He accounts for it as follows : The endo- 

 style of Salpa has been very carefully studied by Hermann Fol, 

 wiio demonstrated, by means of carmine suspended in water, that 

 it threw out a constant stream of mucus when excited by the 

 presence of nutritive material in the same water, with a reflex 

 action like a salivary gland. The mucus is, by an arrangement 

 of cilia, spread out like a curtain over the inner surface of the 

 branchial sac, when it acts as a means for catching the food 

 particles from the ingurgitated water. B3' the action of ciliary 

 bands bordering the groove of the endostyle, the mucus is swept 

 towards the oesophagus, and as it approaches this, it is, by means 

 of the stiff cilia on the sides of the gill, twisted into a thread, and 

 carried by a continuation of the aforesaid bordering bands, 

 through the oesophagus, into the stomach. Now in studying a 

 series of sections of a Salpa which had had abundant food, we 

 find as we approach the oesophagus a mass of material answering 

 to the description of Korotneff's " rhizopod." It takes staining 

 readily and may be traced backward into and through the oesoph- 

 agus, stomach and intestine. As the sections approach the 

 rectum, however, the mass graduall}^ ceases to take staining, and 

 is much more distinctly marked out from the intestinal wall, 

 having had all the organic matter digested out, and consisting 

 only of the inorganic remains, which do not stain. The alimen- 

 tary matter of Salpai is composed of animal and vegetal elements 

 in nearly equal proportions, and the microscope reveals the cal- 



