606 ROBERT MATHESON 



at the end of the larval life. The partially broken down fibers 

 (sarcolytes) are taken up by means of the protoplasmic expansions 

 of the amoebocytes (leucocytes of other authors) and carried by 

 them to all parts of the body where regeneration is in progress, 

 furnishing the necessary nutrition. These are the so-called ' Kor- 

 chenkiigeln/ by Berlese designated sarcolytocytes. The sar- 

 colytqcytes are found only in the more highly specialized insects. 

 Within the sarcolytocytes no digestion takes place, they simply 

 act as carriers of the debris. The muscle nuclei, with their cyto- 

 plasm, become independent cells. The nuclei fragment, each 

 forming a mass within its own enveloping membrane (sarcocyte) . 

 These sarcocytes play an important role in the histogenesis of the 

 imaginal muscles. 



The metamorphosis of the intestinal muscles of insects has been 

 investigated by several workers. In nearly all the dipterous 

 forms they are destroyed by phagocytes without a previous chem- 

 ical change visible under the microscope (Kowalevsky, Van Rees 

 and Perez). Vaney ('02) thinks there is a chemical change within 

 the muscle before the leucocytes become active (in Gastrophilus) . 

 Thompson ('05) finds no phagocytosis in Culex. In all the Coleop- 

 tera so far studied there has not been found any phagocytic activ- 

 ity, the muscles apparently liquefying in place (Karawaiew '99, 

 Breed '03 and Deegener ^04). In the Hymenoptera Karawaiew 

 ('98) and Van Leeuwen ('07) hold to the chemical and physical 

 hypothesis, while Perez ('02) finds phagocytosis in Formica. In 

 the Lepidoptera Korotneff denies any phagocytosis while Verson 

 ('05) and Deegener ('08) find phagocytic activity following a chem- 

 ical dissolution. In the Trichoptera Russ ('08) thinks there is 

 present a form of auto-phagocytosis though he is doubtful of his 

 interpretation of the process in the species (Anabolia laevis) 

 studied. 



In Corydalis the fore-gut possesses a well developed muscular 

 system. The fibers are all cross striated, the striations standing 

 out very clearly. During the prepupal period there are no visible 

 changes until about the time of the loosening of the larval intima. 

 At this time the muscles become strongly contracted, as is shown 

 by the frequent crenulate condition of the sarcolemma and the 



