486 MONTGOMERY. [Vol. XV. 



duct and of the distal portion of the cell are as a rule the first 

 portions to become differentiated into the secretion. At the 

 end of the prophase the cell has attained its maximum size, 

 and the duct its greatest diameter, both containing hundreds 

 of the mature secretion corpuscles lying in an unstained, struc- 

 tureless fluid. The duct in all stages is always larger at its proxi- 

 mal than at the distal end, though it narrows very gradually. 



But the most interesting morphological changes are those of 

 the nucleus. While the secretion is being produced in the 

 cytoplasm the nucleus increases rapidly in size, and at the 

 same time becomes very irregular in form, until in the nearly 

 physiologically mature cell it attains enormous dimensions and 

 sends out through the substance of the cell long branching 

 processes, which anastomose with one another and some of 

 which reach even to the cell membrane (Figs. 178-196). Kor- 

 schelt has described ('89) branched nuclei in the spinning glands 

 of certain insect larvae, which are somewhat similar to the 

 nuclei here delineated. The nucleus attains its greatest dimen- 

 sions and its most marked degree of ramification when there 

 is the greatest amount of the homogeneous substance in the 

 cell, i.e., just before this substance becomes metamorphosed 

 into the secretion corpuscles. At this stage we find the greater 

 portion of the nucleus situated at the proximal part of the 

 cell, and from that point it sends out irregular branches which 

 envelop the mass of homogeneous substance, and which pene- 

 trate into it. At this period, further, no two nuclei are alike 

 in form, so that it would be in vain to attempt to figure all 

 the shapes which they may assume. The nuclear membrane 

 becomes very thin, often scarcely perceptible, around the 

 branched processes. I know of no other nuclei which are more 

 interesting in point of size and variability of form than these ; 

 and it would well repay accurate investigation in the endeavor to 

 decide in what way they may influence or modify the cytoplas- 

 mic changes which are simultaneously taking place, for they 

 obviously have a close physiological connection with the forma- 

 tion of the cellular secretion. Since the nucleus undergoes a 

 rapid process of growth in these stages, we are obliged to 

 assume that it is taking up substances from the cell body ; but 



