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TEXT-BOOK OF ENTOMOLOGY 



eye-buds is situated a nervous expansion which is connected by a 

 nerve with the supraresophageal ganglion. This nerve becomes the 

 optic nerve of the perfect animal, while the optic ganglion is clearly 

 separated from the brain. 



In the anterior, more cylindrical or tube-like part of the brain- 

 appendage we find the " frontal buds " (ss), on which the antenna! 

 rudiments (at) soon bud out, in exactly the same way as the rudi- 

 ments of the limbs arise from the imaginal buds. 



Originally (Fig. 628, A) the brain-appendages lie tolerably far 

 behind in the thorax of the larva, so that they connect the hinder- 



1 as< 



FIG. 628. Diagrammatic representation of the position of the imaginal buds in the larva (A) 

 and pupa (J?) of Musca (the wing rudiments omitted): as, eye-buds; at. aiitciinal germs: t> l -b*, 

 germs of the legs; bg, central ganglionic cord ; g, brain ; A, so-called frontal append:iirr (liii-inin- 

 hang); m, peripodal membrane; o, opening of the frontal appendage into the pharynx; of. 

 i^ophagus; p, so-called "pharynx"; r, rudiment of the proboscis; *, frontal bud; s/. stalk-like 

 connection of the peripodal membrane with the hypodermis ; /-///, 1st, 2d, and 3d thoracic seg- 

 ments. Adapted from Van Kees, by Korschelt and Heider. 



most part of the wall of the pharynx with the foremost section of 

 the brain, which they surround in the form of a mushroom. After- 

 wards, however, subsequent to pupation, they move, together with 

 the central nervous system, farther forward (B), whereby they (if 

 we have correctly understood the descriptions of Weismann and 

 Van Rees) laterally surround the pharynx with their anterior 

 end, which is somewhat ventrally bent. At the same time, there 

 becomes established a gradually widening communication (B, o) 

 between the brain-appendage and the pharynx, which soon extends 

 in the form of a lateral pharyngeal fissure along the entire length 

 of the brain-appendage. As a result, the cavity of the brain- 



