igo8] Muscle Atiachmcnt in Insects 269 



•conditions such as to preclude the purely hypodermal origin of 

 these fibrils. 



A number of writers, notably Tower, '06, have called attention 

 to the fact that when the cuticula loosens, its attachment persists 

 longer at the point of attachment of the muscles than elsewhere 

 and they have thought to see in this proof of the view that the 

 muscles were attached directly to the cuticula. Such evidence 

 is by no means conclusive for as in the instances mentioned above, 

 this condition might very well prevail in either case. 



The whole problem is one of great interest and, as stated at 

 the outset, can be by no means regarded as closed. I cannot 

 believe with Sinety that we have the anomaly of both methods 

 occurring within different species of even the same family of 

 insects. The evidence very strongly supports Maziarski's view 

 that the so-called muscular fibrils passing through the hypodermal 

 cells are in reality modifications of its own protoplasm, — true 

 tonomitomes. 



BIBLIOGRAPHY. 



For an extended bibliography see Snethlage's paper. There 

 are given below only the papers referred to which are not listed 

 by Snethlage. 



1906. Berlese, A. Gli insetti. i, pp. 471-472. Brief review of Berlese, '01, 



and Silvestri, '03. 

 1903. Maziarski, S. Sur les rapports des muscles et de la cuticle chez les 



Crtistaces. Bull. Ac. Sc. de Cracovie, 1903, pp. 520-531. PI. 14. 

 1889. Rees, J. van. Beitrage zur Kentniss der inneren Metamorphose von 



Musca vomitoria. Zool. Jahrb. Anat. iii, pp. 106-108 and tig. 14. 



1905. Snethlage, E. Ueber die Frage von Muskelansatz und der Herktmft 



der Aluskulatur bei den Arthropoden. Zool. Jahrb. Anat. xxi, pp. 

 495-514. Pis. 29-30. 



1906. Tower, W. L. Observations on the changes in the hypodermis and 



cuticula of Coleoptera during ecdysis. Biol. BtiU. x, pp. 188-189, and 

 figs. 8, 10, 11. 



EXPLANATION OF PLATE XXIV. 



Fig. 1. Muscle attachment in the nymph of Chortophaga viridifasciata, 

 an Acridid. 



Fig. 2. A portion of the body-wall of a nymph of Anax, showing the 

 greatly elongated hypodermal cells at the point of attachment of the muscles. 



Fig. 3. Muscle attachment in another individual of Anax. 



Fig. 4. A preparation of Anax from which the cuticula has been broken 

 away, showing the frayed-out ends of the hypodermal cells. 



Fig. 5. An apodeme of a nymph of Anax, showing the greatly elongated 

 hypodermal cells at the point of attachment of the developing muscle. 



Fig. 6. The same, enlarged 



