84 • JOURNAL OF THE 



root-galls, make a very thin shaving from the cut end and pre- 

 pare it for examination with the microscopp, the micro-charac- 

 ters of the disease will be revealed. Fig. 36, Plate YI, represents 

 such a preparation magnified; a and b represent two female 

 cysts; a is mature, b is in an earlier stage of development. If 

 the female cyst is very old the cavity in the tissues of the root 

 will be seen to be occupied by young thread-like worms — the 

 larvae, and eggs in different stages of development, floating in 

 a semi-fluid, granular, gelatinous substance, the amorphic; re- 

 mains of the parent worm. See Fig. 37, Plate YL If the 

 knife in making the section should pass through a young female 

 cyst, the cavity would seem to be occupied by granular proto- 

 plasm and numerous small fat globules, or, as in many instances 

 is the case, the long tubes of the uterus and ovaries with young 

 ova in different stages of development may be seen. If the 

 knife should pass by the side of the animal without injuring it 

 the cavity would then contain a perfect animal variable in form 

 according to age or the character of the surrounding tissues of 

 the root. See Fig. 29, a and 6, Plate Y ; Figs. 36, a and b ; 40, 

 a, and 41, r/, Plate YI. 



In order to understand the real nature of the cysts, and the 

 effect produced upon the growth and structure of the deformed 

 root, it will be well to note the form and general characters of 

 the mature female cyst, and then follow with a detailed account 

 of the development, transformations and habits of the sexes, 

 which forms one of the most wonderful and interesting subjects 

 it has ever been my lot to investigate. 



lY. 



GENERAL CHARACTERS OF THE MATURE FEMALE CYST. 



I have selected the mature female cvst as a preliminarv studv 

 because of its comparatively large size as compared with the 

 males or young, because it is so much more easily found than 

 the males, and almost any one who has a low power microscope 

 at hand can demonstrate with ease the general characteristics 

 here given. 



