REPORT OF THE STATE ENTOMOLOGIST I9IO 87 



Respiratory system. The tracheal trunks comprise a double series 

 on each side extending nearly the entire length of the body and 

 sending minute branches to lateral spiracles on the fourth to the 

 eleventh body segments. The dorsal trunks are united to each other 

 by transverse tracheae in the posterior third of body segments five 

 to eleven inclusive and, in addition, send minute branches to the 

 various organs of the body. The tracheal system of a living, 

 semitransparent larva may be easily examined in a water mount. 



Nervous system. This is composed of the pyriform submedian 

 optic lobes and the fuscous, lobulate, socalled ocular spot, the bi- 

 lobed brain in the fourth and fifth body segments and a series of 

 ganglia united by submedian nerves as follows : A broadly oval 

 ganglion occupying the length of the third body segment and with 

 a width fully equal to half its diameter ; a shorter, more slender 

 ganglion in the anterior portion of the fourth segment ; a broadly 

 pyriform ganglion in the anterior third of the fifth body segment. 

 Separated slightly therefrom, another ganglion lies in the posterior 

 portion of the fifth and the anterior part of the sixth body seg- 

 ments. It is a little narrower than the preceding though it has an 

 equal length. The fifth and sixth ganglia, each short, subquadratc, 

 occur in the sixth body segment ; the seventh ganglion is one-half 

 longer than the sixth and is situated in the middle of the seventh 

 body segment ; the eighth to the twelfth body segments each appear 

 to have one ganglion, the posterior one almost extending to the 

 anterior margin of the thirteenth body segment. 



Digestive system. The digestive system, difficult to study because 

 of its being largely inclosed by nearly opaque adipose tissue, consists, 

 according to Kahle, of a comparatively simple tube extending the 

 entire length of the body, the granular salivary glands occurring in 

 the fifth to the ninth body segments, while the long, slender, 

 malpighian tubes may be found in the nth to 13th segments, 

 inclusive. 



History of pedogenesis. The discovery of this remarkable 

 phenomenon is credited to Nicolas Wagner, professor of zoology 

 at Kasan. He published a short note in the Journal of the Univer- 

 sity of Kasan in 1861 or 1862, and in 1865 a detailed account. The 

 latter was held by the editor for almost two years because of its 

 *' almost increditable " character. The observations of Wagner 

 were confirmed by Meinert and Pagenstecher in 1864, and by Hanin, 

 Leuckart and Mecznikoflf in 1865. Wagner believed at first that 

 the embryos originated in the adipose tissue, at the expense of 

 which they develop very largely. Later he, Leuckart and Meczni- 

 kofif satisfied themselves that the embryos originated from ovaries. 



