REPORT OF THE STATE ENTOMOLOGIST I9IO 95 



nd observed the embryos and their various stages of develop- 

 lent, photomicrographs being successfully made from this living 

 laterial. 



The observations on the small lots of material noted above were 



lecked by examinations of the fruit jars containing larger amounts 



f material. The latter jars were especially useful because the very 



umerous maggots made it possible to select at one time practically 



11 stages, which were mounted in considerable abundance. Some 



f the larvae were cleared with potassium hydrate and then stained 



ith Fuchsin, Hematoxylin, Eosin and Eosin-Hematoxylin. The 



ctions of the stains were all somewhat unsatisfactory and the 



majority of our most successful mounts were entire larvae in 



irdinary balsam preparations which had been thoroughly cleared. 



he study of the mounts was checked by examination of living 



material as detailed above. 



Embryology. The development of the embryo may be observed 

 n the living larva. It is easily seen in the larger, white individuals 

 :ommon in the fall and producing a number of young, though the 

 :hanges in the embryo are best observed in the small, yellow lar- 

 va.t, especially if they are mounted in shallow water cells. ^ 



The region of the ovaries is marked in the large, white larvae by 

 an irregular, yellowish green streak in the tenth or eleventh seg- 

 ments. A close examination of such a larva may disclose the oval, 

 large-celled ovaries nearly concealed by the submedian masses of 

 Dpaque, white adipose tissue, especially if the larva rolls slightly. 

 Fhese organs are more easily detected in the young yellowish 

 larva. They are submedian, whitish transparent, contrast rather 

 strongly with the darker, more refractive adipose tissue and are 

 located in the posterior portion of the tenth or the anterior part 

 Df the eleventh segment, one frequently being somewhat in advance 

 3f the other. They are composed of globular or oval, nucleated 

 :ells. 



The youngest embryos we have observed are oval, granular and 

 may be found in the large, white larvae in the vicinity of the 

 ovaries. The motion of the internal organs appears to distribute 

 the embryos through the body, there being from one to as many 

 as seventeen in individual mother larvae. The young embryos are 

 semitransparent and present a strong contrast to the opaque adi- 

 pose tissue of the large, white larvae or the denser cells of the 

 small, yellowish larvae. The youngest embryo photographed is 



1 We have used a ring of vaseline to support the cover glass and found 

 ;uch a cell very satisfactory as well as economical. 



