HISTOLOGY AND DEVELOPMENT OF MYEIOTHELA PHRYGTA. 525 



presence of sense-cells and cilia in its upper part, and of 

 numerous glandular cells, the goblet-cells, in its lower part. 

 (2) A middle zone comprising the middle region of the entire 

 animal, and characterised by the presence of numerous gland- 

 cells. (3) The blastostyles and the foot region, where the 

 endoderm is almost exclusively composed of vacuolate cells, 

 usually loaded to the full with stored nutritive material in the 

 form of nutritive spheres. 



Of the function of the goblet-cells I can say little. From 

 their position I had supposed that their stored material was 

 discharged when the food was first received, and that they were 

 concerned in the elaboration of a digestive ferment or ferments. 

 But I have found them apparently unaltered in animals which 

 have just taken in their prey (a crustacean). The glairy, 

 sticky appearance of the contents of the expanded portion of 

 the goblet, however, suggests the idea that they form a strongly 

 adhesive surface to what may be called the prehensile portion 

 of the endoderm. The gland-cells, on the other hand, present 

 no especial difficulties. Fig. 18 a represents one shrunken and 

 discharged as seen in an animal at the close of a digestive act, 

 that is with merely the detritus of a meal in its enteric cavity. 

 Fig. 18 shows one taken from a fasting animal. It is fully 

 loaded with granules. Fig. 18^ represents an intermediate con- 

 dition. The granules are large and coarse, and appear to be 

 formed in the deeper portions of the cell. Their discharge is 

 characteristic, and may be witnessed in preparations from an 

 animal which has just ingested its prey. The granules are 

 extruded, apparently unchanged, into the somatic fluid, there 

 to be dissolved. That is to say, they do not break down to 

 form the digestive enzymes until they are free from the cell in 

 which they were formed (fig. 21). 



The Process of Digestion. — For a long time I was 

 unable to determine the natural food of Myriothela, while at 

 the same time all endeavours to induce it to ingest pieces of 

 raw meat or fragments of Molluscs and Crustacea completely 

 failed. I therefore, in the meantime, turned my attention to 

 carmine and sodium sulphindigotate, and with a fine pipette, 



