655 



Leu- 



The walls and solid portion of the tumor are composed of cuboidal 

 epithelial cells the nuclei of which are very prominent. These cells 

 are supported by a rich growth of stroma (connective tissue), which 

 is equally evident in the branching 

 tufts or finger -like processes. In 

 the larger lobes there were found 

 several places where numerous leuco- 

 cytes (Fig. 4 Leu) were collected 

 possibly indicating a state of in- 

 flammation. 



Many of the nuclei were un- 

 dergoing division mitotically but I 

 was not able to find well formed 

 centrosomes nor spindle fibres. The 

 chromosomes exhibit a great variety 

 of combinations. In one (Fig. 5) io the early anaphase there were 

 4 distinct chromosomes but there was also in the same field under 

 the oil immersion lens a dividing cell in which I could not make out 



Fig. 4. A microphotograph of the 

 adrenal tumor in the frog. Leu leuco- 

 cytes. 



Fig. 5, Nuclei showing mitosis characteristic of this adrenal tumor. 



any definite number of chromosomes. A careful study of the nuclei 

 in various parts of the tumor revealed the fact that the cells were 

 dividing rapidly but in nearly every instance atypically, i. e. the chro- 

 matin passed through various abnormal stages and it was impossible 

 to classify them into any definite processes; for example in one cell 

 there were undoubtedly 14 chromatic processes extending in all di- 

 rections from a central mass of chromatin like a rosette while in 

 others there were frequently many more. 



Not only do these atypically dividing cells give rise to different 

 forms of nuclei but also small bodies in the cytoplasm taking a basic 

 stain are frequent (cf. Young '97, p. 10) which are probably to be 

 interpreted as chromatic masses that were not included within the 

 nucleus as it assumed the so-called "resting state". 



