Communications. 281 



Throughout May the habit of the oospores appeared to change 

 remarkably, for instead of producing zoospores they protruded a 

 thick and generally jointed thread, agreeing in size exactly with 

 the average Peronospora inft&tans threads. * * * At the be- 

 ginning of May, while observing the habit of Fusisporiura and 

 its resting state, I observed typical Peronospora infesians growing 

 upon the drier parts of the year's crushed and decayed leaves; 

 this observation was confirmed by Mr. Vize, who wrote on May 

 22d : " According to my examinations the Peronospora are on the 

 drier parts of the magma. I do not observe it growing on the 

 very wet." * "^ * Mr. Chas. B. Plowright (surgeon of King's 

 Lynn, a gentleman who has long studied fungi) has patiently ex- 

 amined some of the living material with which I have been work- 

 ing this spring and early summer, and he writes me on May 19th : 

 "I find plenty of branching, nodose conidiophores, especially 

 among the drier portion of the substance sent. I also found 

 living conidia. I have many conidiophores with convoluted 

 bases, but in the vast majority' of cases long ere the conidia come, 

 the oospore is gone; I see the gran alar protoplasm distinctly 

 ascending the base of the conidiophore." As regards the first 

 coil of my mycelium, Mr. Plowright writes: "I distinctly saw 

 this curved in two oospores, and I believe the m-ycelium comes 

 out with a curl." The same gentleman, under date of May 19th, 

 writes: "I saw a great many conidiophores, both with conidia 

 in situ and not; most of the conidia had fallen off ; latterly I saw 

 plenty of convoluted bases." The evidence of identity seems com- 

 plete, and much data here published, as well as much as yet unpub- 

 lished, has been confirmed by ^lessrs. Vize and Plowright. * * * 

 On examining the oospores in saccharine fluid, I observed some 

 of the discharged bladders to be carrying from two to four sec- 

 ondary bladders inside ; these inside bodies were in their turn ex- 

 pelled and grew and produced mycelium, while a few bursted and 

 produced from three to six very small zoospores, generally but 

 three. It is a most singular fact that these secondary bladders 

 and zoospores are exactly the same in size with De Barry's 

 Pyihium vexans and about one-sixth or one-eighth of bulk of the 

 resting spores from which they are discharged. With this excep- 



