568 GEORGE H. BISHOP 



INTRODUCTORY 



The honey-bee larva, just at the beginning of pupation, ex- 

 hibits in the cell of its fat-tissue an abrupt and striking cytological 

 transformation. The nuclear wall disappears, and the peripheral 

 fat-vacuoles of the cell approach the nucleus; through the 

 interstices between these, granules of basophile material, pre- 

 sumably of the nature of nucleoli, pass from the nuclear area 

 and invade the cytoplasm as chondriosomes. By progressive 

 absorption, both of the surrounding cytoplasmic matrix and 

 of its fat-vacuoles, these granules finally develop into globules 

 containing albuminoid material, which are discharged into the 

 blood on dissolution of the cell wall. The nuclear membrane is 

 meanwhile reformed, without nuclear division, and may persist 

 until after disintegration of the cell wall and discharge of its 

 contained globules. 



The cytological structure of these fat-body cells, or trophocytes, 

 will be described in the following account, and especially the 

 cytolytic changes they undergo during larval pupation. It has 

 seemed advisable to enter in the second part of this paper, into 

 certain rather speculative considerations which, based on the 

 work so far accompUshed, form the tentative framework for 

 further research; but no attempt is made at this stage of the 

 investigation to propound the ultimate analysis of cell metabolism 

 in the insect fat-body. 



The stud}^ of somatic cell metabolism has led to a wide diversity 

 of interpretation, depending on the point of view of the special 

 research deahng with it. The result has been a 'chemical' 

 theory of function, or a 'physical theory,' or a 'genetical' theory, 

 when an adequate biological interpretation must involve all 

 of these. Especially in general physiology and physiological 

 chemistry does a large and rapidty augmenting body of data, 

 specifically applicable to the functioning of the somatic cell, 

 invite a reconsideration of normal 'resting' cell structure; it 

 demands, in fact, a more energetic name for the 'resting' cell 

 itself. As a method of coordinating these specialized studies, 

 it should be profitable to subject some one tissue to as many 

 different techniques as conditions admit of, and the bee fat-body 



