1 



Vol. XXIII. September, 1912. No. 



BIOLOGICAL BULLETIN 



A CONTRIBUTION TO OUR KNOWLEDGE OF THE 

 FUNCTION OF THE (ENOCYTES OF INSECTS. 1 



R. W. GLASER. 



The function of the cells known as the oenocytes has been 

 the object of a considerable amount of speculation by various 

 investigators. The studies which constitute the basis of these 

 speculations have all been of a morphological character and, 

 while valuable in their w r ay, throw no light on the physiology of 

 these very singular elements. So much has been written about 

 them, especially about their morphology, that we will consider 

 only a few of the more interesting views on their possible function. 

 In 1873 Graber called attention to the fact that the oenocytes 

 are glands secreting a substance concerning which nothing is 

 known. Later ('91) he supposed that they are metamorphosed 

 into the fat-body, and also give rise to blood corpuscles. This 

 was corrected by Wheeler, in 1891, who through a study of the 

 embryological development of these cells, concluded that they 

 neither give rise to the fat-body nor to the blood. Pantel ('98) 

 and Berlese ('99) endowed the oenocytes with an excretory 

 function, the latter supposing that they serve during the periods 

 of moulting and pupation when the Malpighian tubules are 

 functionless. Anglas ('oo) advanced the view that the oenocytes 

 may possibly secrete ferments. Koschevnikov ('oo) makes the 

 remarkable statement, among others, that he has preparations 

 which show plainly that the oenocytes swallow fat cells. He 

 further says, "unnecessary substances which get into the blood 

 stop in the interior of the oenocytes in the form of granules. The 

 cells are not periodically emptied of this excretion product, but 



1 Contributions from the Entomological Laboratory of the Bussey Institution, 

 Harvard University. No. 57. 



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