JOURNAL OF MICROSCOPICAL SCIENCE. 
EXPLANATION OF PLATES XIX & XX, 
Illustrating Mr. Worthington G. Smith’s paper on the 
Resting-Spores of Peronospora infestans, Mont. 
PLATE XIX. 
Photographs showing the oogonia and antheridia of Peronospora infestans 
in conjugation, x 300 diam. It will be found of advantage to 
examine them with a magnifying lens. 
PLATE XX. 
Key To THE PHOTOGRAPHS IN PiLatTE XIX. 
Upper figure. 
A, A, A.—Oogonia, showing the dark coat. 
B.—Ditto; a hypba can here be seen underneath. 
c.—Ditto, sessile oogonium, having the spurious appearance of 
being within the mycelium whilst it is really upon it. 
D, D, D.—Antheridia. 
#.-—Antheridium perfectly mature. 
¥.—Antheridium immature or abortive. 
Lower figure. 
G, G, G.—Oogonia. 
H.—Sessile oogonium as in figure above (c). 
J.—Oogonium burst by the sun’s rays whilst being photo- 
graphed. 
K, K, K, K, K.—Antheridia. 
