368 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
rarely possible to confirm the results of another investigator’s work more 
completely than Rengel’s results have been confirmed by my own 
investigation. 
The results of De Bruyne’s (97) investigation of Tenebrio may be 
entirely disregarded, because there can be little doubt but that he has 
mistaken the fundamental nature of the changes with which he was 
dealing. Misled by the similarity in appearance of cross sections of 
metamorphosing muscles (such as my Figure 15, Plate 6) to cross sec- 
tions of the degenerating muscles of Muscidae (see figures given by 
Kowalevsky, ’87, Van Rees, ’88, and others), he has concluded that the 
muscles in ‘l'enebrio likewise degenerate. As a matter of fact, there can 
be no doubt but that he was dealing with metamorphosing muscles 
which retained their individuality thoughout pupal life, as is indicated by 
Kriiger’s (98) results on the same insect, as well as by the present study 
of Coleopterous forms. The probability is that his leucocytes, which 
he found engulfing fragments of muscle, are the same as the tracheal cells 
of the present paper, and that his ‘“ Kornchenkugeln’”’ are the same as 
the detached fat cells described by Kriiger (’98, p. 16). 
Kriiger (98) was venturesome in generalizing from such meagre data, 
but his conclusion is entirely confirmed by the present research. All of 
the imaginal wing muscles are metamorphosed larval muscles, though 
some of the other metathoracic muscles nearby are not. However, it is 
questionable if the cells which Kriiger (’98, p. 17) describes as “ Weis- 
mannsche Kornchenzellen” are such in reality. He has given us no 
evidence to support the view that the inclusions in these cells are 
muscle fragments. Other, just as probable, explanations of the nature 
of these cells might be given. 
Karawaiew’s statement (99, p. 202), that he finds no shegéeskae 
of the muscles of Anobium, agrees with what has been found in 
Thymalus. 
It was impossible to explain the disagreement of Berlese’s results with 
the results of the present research, until a copy of his last paper (:02*) 
was received. His idea, that there is, in the metamorphosis of the 
muscles of all the metabolic insects: first, an emigration of nuclei from 
the larval muscles; secondly, a formation of “ sarcocytes”’ from these ; 
thirdly, a transformation of these “sarcocytes ” into ‘‘ myocytes ;” and, 
finally, a production of new muscles from these, meets a fatal objection, 
as far as Coleoptera are concerned, when the anatomical changes of 
these muscles are considered. The first half of my paper is taken up 
with tracing individual larval muscles in their metamorphosis into 
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