346 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



(the metamorphosing muscles of Aiiglas), or they may emigrate and form 

 muscles elsewhere in the body (the degenerating muscles and the muscles 

 of new formatiou of Auglas). 



No very important generalizations can be made from this review. 

 The subject has reached a stage where it is evident that the muscular 

 changes differ in the various groups of insects, and that not all of the 

 muscles of the same insect undergo the same changes. Yet the impor- 

 tance and significance of these differences are not known. Comparative 

 researches are therefore needed. Two of the investigators have already 

 attempted such researches, but both attempts are unfortunate. De 

 Bruyne's results, both his observations and his interpretations of the 

 phenomena observed, have already been shown by Berlese to bo untrust- 

 worthy. Berlese has given us an elaborate memoir full of interesting 

 observations, and as accurate as could be expected when the phenomena 

 observed are so complicated. His interpretations of these phenomena 

 are not so fortunate, however. Judging from my observations on Cole- 

 optera, as well as from personal observations on all of the groups of in- 

 sects which he has studied, and from the numerous authors whose 

 interpretations of phenomena lie has contradicted, his fundamental idea 

 of the formation of " sarcocytes " from the larval muscle nuclei, and the 

 development of imaginal "myocytes" from the "sarcocytes" is not true 

 in many cases, if at all. The reasons for this statement, as fiir as Cole- 

 optera are concerned, will be given in detail in discussing the results of 

 the present paper, while the results of my comparative studies on other 

 insects I hope to publish in the not far distant future. The fundamental 

 correctness of the interpretations of the present paper, as contrasted with 

 those of Berlese, is indicated by the fact that they are in complete accord 

 with the statements of three (liengel, Krliger, Karawaiew) of the seven 

 authors who have previously mentioned these changes, while the results 

 of Berlese are not in accord with those of any of the other investigators. 



Some confusion has arisen from the careless use of the word " Korn- 

 chenkugeln," for which there is no really satisfactory English equivalent. 

 Some authors have used it to signify {jny leucocyte containing solid 

 bodies of whatever nature, or, worse yet, some have used it in cases 

 where it does not appear that the cells in question are even leucocytes. 

 The " Kijrnchenkugeln " which Weismanu found and so called are leu- 

 cocytes containing fragments of muscle, either pieces of the contractile 

 substance or occasionally muscle nuclei. As this is the generally accepted 

 use of the word, carelessness in its use ought not to be permitted. With 



