REPORT OF THE STATE ENTOMOLOGIST I9IO 95 



and observed the embryos and their various stages of develop- 

 ment, photomicrographs being successfully made from this living 

 material. 



The observations on the small lots of material noted above were 

 checked by examinations of the fruit jars containing larger amounts 

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

 numerous maggots made it possible to select at one time practically 

 all stages, which were mounted in considerable abundance. Some 

 of the larvae were cleared with potassium hydrate and then stained 

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

 actions of the stains were all somewhat unsatisfactory and the 

 majority of our most successful mounts were entire larvae in 

 ordinary balsam preparations which had been thoroughly cleared. 

 The study of the mounts was checked by examination of living 

 m^aterial as detailed above. 



Embryology. The development of the embryo may be observed 

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

 common in the fall and producing a number of young, though the 

 changes in the embryo are best observed in the small, yellow lar- 

 vae, 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 

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

 These 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 

 of the eleventh segment, one frequently being somewhat in advance 

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

 cells. 



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 



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

 such a cell very satisfactory as well as economical. 



