336 STEFAN KOPEC. 



grafted an analogous germ derived from a full-grown caterpillar, 

 which was to undergo metamorphosis in a few days. In two of 

 the caterpillars somewhat large and black outgrowths dwarfed 

 and deformed wings appeared on the place of grafting, 'in their 

 uniformly dark hue and the thickness and markings of the chitin 

 they formed a striking contrast to the bright-colored tegument of 

 the caterpillar. (Cf. Fig. D.) The small size and the abnormal 



FIG. D. 



forms were doubtless caused by inevitable injuries of the delicate 

 germ during transplantation, as well as by the difficulty of extract- 

 ing the pupal wing from the moulting but not pupating caterpillar. 

 Histologically the development of the pupal wings was normal. I 

 have also formerly observed (Kopec, 'n) that the sexual glands 

 of full-grown caterpillars develop at their normal rate when grafted 

 on the caterpillar after their third or fourth moult. Such a be- 

 havior of the grafted wings and sexual glands strikingly confirmed 

 the above-stated principle that after the time when the brain has 

 already exerted its influence on the whole organism which influ- 

 ence decides the inception of histolytical processes leading to the 

 chrysalis stage the subsequent development and metamorphosis of 

 organs is quite independent of the brain. 



The results of my experiments proved that the rate of develop- 

 ment of the grafted organs underwent no change due to the in- 

 fluence of new surroundings, differing both as to age and physio- 

 logical state. These results seem to disagree with analogous re- 

 searches of Uhlenhuth ('12, '13) on amphibians. This author 

 grafted eyes of salamander larvae on specimens of a different age 

 and came to the conclusion that the metamorphosis of the trans- 

 planted eyes underwent a distinct retardation when grafted on 



