POTATO-FUNaUS. 149 



The PoTATO-FTJJsrGirs. — Last autumn (1875) Mr. C. Edmund 

 Broome, of Batheaston, selected a number of Potato-leaves badly 

 diseased with Peronospora infestans, Mont., and repeated my experi- 

 ments. The leaves selected by Mr. Broome vrere only those infected 

 with Peronospora ; these Mr. Broome partly crushed and placed in a 

 saucer of water under a bell-glass. The water was kept in a sloping 

 position, so that only part of the magma was in the water ; and the 

 following is the result up to the present time : — The mycelial threads 

 (from my observations doubtlessly &f the Peronospora) ramified in every 

 direction and produced, upon distinctly septate threads having no 

 anatomical connection with each other, oogonia and antheridia precisely 

 as described by me, and agreeing with Artotrogns. From last autumn 

 till now (21st April, 1876) the oospores have gone on maturing, and 

 are now generally rough in outline, rich brown in colour, and still 

 hyhernating ; agreeing in every particular with the present condition 

 of the bodies which I have myself preserved, Tiie true Peronospora 

 conidiophores have not been so sensitive of decay as to perish in the 

 water, for they still abound in the magma together with the normal 

 Peronospora conidia. So carefully has the experiment been carried 

 out by Mr. Broome, that there is scarcely any trace whatever of 

 foreign Fungi ; the whole magma is one mass of decayed leaf-cells, 

 Peronospora conidiophoi'es and conidia, and resting-spores. At an early 

 date De Bary's notes and criticisms will be properly answered, and 

 complete mounted materials distributed amongst botanists. — Woe- 

 THiNGTON G. Smith. 



HESE.illCKES I2iT0 THE NATURE OF THE POTATO- 

 FUNGUS, PHYTOPHTEORA INFESTANS. 

 Br Professor A. de Bary, of the University of Strasbourg. 

 ( Continued from p. 126.) 



Here I may mention that this year I found the Potato-fungus on 

 an exotic species of ScrophulariacecB, viz., Sehisanthus Grahami, on 

 which, so far as I know, it had not been observed before. It appeared 

 on this ornamental plant in a garden outside Strasbourg, belonging to 

 Dr. Stahl, in the end of July, when the Potato-fields had been exten- 

 sively attacked by it. The phenomena of destruction were the same 

 as in the Potato-plant in stalks, leaves, and buds; the development of 

 the Fungus was of extraordiuaiy luxuriance, but here, also, no oogonia 

 were found. This example, at any rate, reveals to us a new host for 

 the Phytophthora, and demonstrates the possibility of other species 

 being found in which it may grow not only luxuriantly, but also form 

 oospores. The fact that ScJiizantlms Grahami is a Chilian plant, and, 

 therefore, indigenous to the same region as Solanum tuberosum and its 

 allies, may not, perhaps, be of any great importance in this connection, 

 still it should be noticed. 



It is, perhaps, not very unlikely that the oospores oi Phytophthora 

 may, in a climate diiferent from that of Central Europe, be found in 

 hosts which do not produce them with us. On that supposition the 



