216 R. W. GLASER. 



eye. In one and two year old larvae they are much smaller, for 

 they grow in size with age as do the other organs. In this species, 

 the cenocytes are located in the seven abdominal segments 

 which are just those which bear the abdominal spiracles. Be- 

 hind these they are situated, occurring in clusteis around the 

 tracheae. There are only two clusters to a segment, one on each 

 side. The number of cells in a cluster varies, from ten to forty 

 or fifty, in different segments. The size also varies considerably 

 in different segments (diameter 175-250^) and even in the same 

 cluster, yet the smallest one far surpasses the size of any other 

 cell within the body of the insect. 



Through the kindness of Mr. Chapman, I was able to obtain a 

 large amount of material and, following the suggestion of some 

 of the previous investigators, principally Anglas and Janet, I 

 began to work on the hypothesis that the cenocytes are unicellular 

 glands, perhaps secreting a ferment. 



A number of tests were made for lipase and oxydase. First, 

 however, to become thoroughly acquainted with the reactions 

 of these enzymes, the pancreases of four hogs were used. Lipase 

 and oxydase are known to occur in these organs, and it was 

 thought advisable to work, with them for a time before applying 

 tests to the cenocytes. The pancreas was cut from the hog 

 immediately after it was slaughtered, so as to be certain that it 

 was quite fresh. An extract of the organ was at once preserved 

 in toluol to keep out all bacterial infection. This extract was 

 then diluted with physiological .65 per cent, salt solution, one 

 part of extract to ten parts of saline solution. To two cubic 

 centimeters of this diluted extract one fourth of a cubic centi- 

 meter of ethyl butyrate was added, plus a small quantity of 

 lacmoid solution. Purified lacmoid crystals were used and the 

 solution was made as nearly neutral as possible. The extract 

 was, of course, kept under the layer of toluol while the other 

 reagents were being added. The specimen w T as then put in an 

 incubator at body temperature and kept there for 24 hours. 

 As a control test a second and aliquot portion of pancreatic juice 

 was boiled in order to kill any enzyme. This was treated with 

 the same reagents in exactly the same manner, and put in an 

 incubator for 24 hours. At the end of this time both specimens 



