1 9 20] WILSON— CROWN -G A LL 63 



tions, and are easily recognized as such upon careful examination. 

 The process of division is clearly mitotic (figs. 46, 48-50, 53-57). 

 Dark bodies suggesting centrosomes are commonly visible in the 

 metaphases at the poles of the spindles (figs. 46, 50). The early 

 divisions of the nuclei in the amoeboid infection stages have been 

 followed with only partial success. The figures correspond to 

 those seen in the later divisions, but average considerably larger 

 (fig. 44). The centrosomes, if the dark bodies at the poles of the 

 spindles are to be called such, are a constant feature in good prepa- 

 rations. Clearly recognizable division figures within the spo- 

 range have been found less frequently. There is some evidence 

 that a division occurs while the nuclei are yet very small (fig. 15), 

 and much better evidence of a division just preceding the forma- 

 tion of zoospores (figs. 17, 48). Whether these are in the nature 

 of reduction divisions must be left for future determination. Care- 

 ful study has failed to lead to a definite conclusion as to the chro- 

 mosome number. In the divisions immediately preceding the 

 formation of the zoospores the number of chromatic bodies seen 

 is apparently four (fig. 48). In all the division figures observed, 

 at whatever stage, the spindle seems to be intranuclear, corre- 

 sponding to the findings of other investigators of members of the 



Chytridiaceae. 



Classification of parasite 



Lagerheim 



crown-gall of alfalfa, classed it in the genus Cladochytriam with 

 the specific name alfalfae. Magnus (21), in his article of 1902. 

 gave strong reasons for removing the organism from that genus 

 and referred it to the genus Urophlyctis, retaining the specific name 

 given by von Lagerheim. The terminology Urophlyctis alfalfae 

 (von Lagerheim) Magnus has been generally accepted in later 

 works. Although Magnus was right in removing the parasite 



from 



in the genus Urophly 



observations. 



Urophly 



in Saccardo's Sylloge Fungorum (7: p. 303) is as follows: 



phlyctis bulla.) Zoospo 



Krypt 



(Etym. oura cauda et 





