CELL INCONSTANCY IN HYDATINA SENTA 461 



GASTRIC GLANDS 



Degeneration of the gastric glands. It is not uncommon in 

 this rotifer to find the gastric glands more or less atrophied. In 

 some cases the change referred to is evidenced merely by the more 

 homogeneous appearance of the organ, and by its failure to take 

 the stain properly. In more marked cases the glands are plain- 

 ly reduced in size, the characteristic structure is lost, and there 

 is no longer any connection with the stomach-intestine. In ex- 

 treme cases one of the glands is entirely missing, and in one 

 specimen I was unable to find either of the glands, though the 

 sections were apparently not damaged in the region proper to 

 these organs. One gland was sometimes atrophied while the 

 other was normal. 



In none of these cases does the degeneration take the form of a 

 destruction of some of the cells (here nuclei, since the gastric 

 glands are syncitia) through high physiological activity. The 

 whole organ degenerates simultaneously, and in the early stages 

 the six nuclei are still recognizable. 



Number of nuclei in the gastric glands. In determining the num- 

 ber of nuclei in the gastric glands only normal specimens were 

 used. The degeneration described above is easily recognized, 

 and specimens with such glands were rejected. 



One hundred and twenty glands were studied. Among this 

 number, nine had other numbers of nuclei than six. Four was 

 the smallest number observed, seven the largest. The frequency 

 of the various number is given in table 6. 



In the case of the gastric glands, as with the yolk gland, it was 

 possible to determine some of the conditions of age, environment, 



TABLE 6 



The frequency of occurrence of various numbers of nuclei in 120 gastric glands of 



Hydatina senta 



