EFFECTS OF DUCTLESS GLANDS ON FLIES 



263 



In the case of egg mass No. 22 of L. sericata the food material 

 was raised to the boiling-point before the eggs were placed on it. 

 The average length of the thyroid pupae was .291 inch; that of 

 the muscle pupae, .303 inch. The distribution of the pupae is 

 shown in table 7. 



TABLE 7 

 Showing the effect on the length of the pupae of Lucilia sericata of feeding the 

 larvae on thyroid. The first line indicates the distribution according to length of 

 the thyroid-fed pupae, the second indicates that of the muscle-fed 



Thyroid 



Muscle 



Length in .OOl's 

 inch 







1 



325- 

 329 



In a number of experiment the effects of thyroid and thymus 

 feeding were compared. Egg masses No. 24 and No. 26 show that 

 thymus probably has an effect upon the size of the pupae. In 

 one lot in whi ch there were 25 muscle pupae and 52 thymus pupae 

 the average respective lengths were .314 and .322 inch (table 8). 



TABLE 8 



Showiiig the effect on the length of the pupae of Lucilia caesar of feeding the larvae on 

 thymus. The first line indicates the distribution according to length of the thymus- 

 fed pupae, the second line indicates that of the muscle-fed 



Thymus 



Muacle 



Length in .OOl's inch. 



5 

 

 340- 

 344 



In another series, however, in which there were 15 muscle pupae 

 and 13 thymus pupae, the respective lengths were .297 and .298 

 inch (table 9). 



TABLE 9 

 Showing the effect on the length of the pupae of Lucilia caesar of feeding the larvae 

 on thymus The first line indicates the distribution of the thymus-fed pupae accord- 

 ing to length, the second line indicates that of the muscle-fed pupae 



