Journal of the Royal Asiatic Society of Bengal Science 1938

As pointed out by WIESMANN such characters as the number of segments differentiated the first appearance of the proctotheum (and the stomodwum) the beginning of the differentiation of the fat body etc. [...] The intensity of the active period which followed 1 was heightened by the invention of the microtome in about 1860 and with it the rapid development of the section-cutting technique. [...] As a result of the inversion the inner or normally dorsal side of the cells abutting in the beginning against the yolk comes to point away from the latter and thus determines the ventral side of the future embryo. [...] In all other groups of insects the inner walls of the cells determine the dorsal side of the future embryo and the outer walls the ventral side. [...] The entire manner including the absence of neuroblasts of the origin of the optic lobes in Locusta and other insects clearly shows that they are not homodynamous with the other two lobes of the protocerebrum nor are theyTABLE 1. The ganglionic composition of the brain of Locusts as compared to a ganglion of the ventral nerve chain.