40 Scientific Proceedings. Royal Dublin Society. 



Nozemia should be abandoned. The name has as yet scarcely had time to become 

 definitely established in the literature ; and there need be therefore ihe less 

 reluctance to revert to former usage, and to unite all the species in the one genus 

 Phytophthora. 



Based on the mode of development of iheir sexual organs, the species contained 

 in the genus may now be grouped as follows : — 



A. — Species in ivliich, so far as is known at ]jresent, the anthcridia lolimi 'present are, 



always ampliigynous : — 



1. 7\ Mj/es/fMis (Mont.) de Bary 7. V. tcrrestria '^hexh. 



2. 7'. Phaseoli Thaxt. 8. P. AlHi Saw. 



3. F. Coloeasiae Eacib. 9. /'. Mclongenae Saw. 



4. P. ^reme (Colem.). ^ 10. P. ^imr^M McEae 



5. P. erythroseptica Pethyb. 11. P. cryptogea Pethyb. and Laff. 



6. P. piarasitica Dastur 



B. — Species in which the anthericlicc are preponclercUingly iKiragynotis, but are 



sometimes amphigynous : — 



12. P. Caetorum (L. and C.) Schroet. 



13. P. Fagi Hartig 



14. P. Syringae Klebahn 



C. — Species in luhich, so far as is known at p)rescnt, the anthericlia are always 



piaragynoxis : — 



15. P. Nicotianae de Haair 



D. — Species in which the mode of development of the scxucd organs is not fully knoimi, 

 or in which these organs have not yet been found : — 



16. P. Thalietri Wilson and Da,\is 20. P. jatro2:>hae Jens. 



17. P. agccves Vill. (?) 21. P. fid Eau 



18. P. Faleri Maubl. 22. P. citri Eau 



19. P. Theolromae Golem. 



P. Thalietri is probably closely allied to P. Phaseoli, and may ultimately be 

 found to belong to Group A. Gandara^ states that a Phytophthora, specified by 

 Villada as P. agaves, causes a disease of Agave in certain parts of Mexico ; but we 

 have not succeeded in finding any description of this species. P. Faheri and 

 P. Theohromae are probably synonymous. According to Coleman, the latter 

 species is, closely allied to P. Arecae ; if this be really so, it should be placed in 

 Group A ; but antheridia are absent, or are only rarely formed ; and it is not 

 certain whether they are amphigynoiis or paragynous. P. jatrophae has been 

 issued in culture form, but apparently has not been described ; it may be identical 

 wir.h P. Nicotianae. P. fid and P. citri were named provisionally in 1915 ; but 

 we are officially iufornred that nothing further has yet been published on them. 



' Mem. y. Rev. Soo. Cient. Antonio Alzale, xxv, 1908-9, p. 293. 



