xlv Description of t lie Figures, 



Plate ATI. 



riG. 



\'1\. Phi/t02^t/i ora ififestafis, gonidiopliove growing into the 

 air through a stoma on the under surface of a jjotato 

 leaf, X 150. 



122. Mature zoosporangium of same, x 400. 



123. Zoosporangium of same showing the protoplasm 



breaking up into zoogonidia, X 400. 



124. Zoogonidia of same, X 400. 



125. A zoogonidium of same, after having retracted its cilia 



and assumed a spherical form, germinating, X 400. 



126. A gonidium of the same germinating; the gonidium 



is morphologically similar to a zoosporangium, but 

 differs in giving origin to a germ, tube direcily, instead 

 of producing zoogonidia, x 400. 



127. CiistopU'< candidus, portion of . mycelium bearing an 



oogonium, a; b, oosphore, which after fertilization 

 secretes a thick, warted wall ; c, antheridiuui ; d, an 

 immature oogonium, x 650. 



128. Mature oosphere or resting-spore of same showing 



escape of zoogonidia ; a, exosporium ; h, endosporium ; 

 c, free zoogonidia ; d, remains of the wall of the 

 oogonium, x 650. 



129. Peronosjjora XKirasitica, showing a portion of mycelium 



parasitic in the tissues of Capsella hursa-iJCiMoris ; a, 

 branch mycelium running between the cells of the 

 host and sending off haustoria into the cells, a. a ; 

 the mycelium is much constricted at the points where 

 it pierces the cell-wall, X 650. 



130. Clubtodadium Brefeldii, portion of a much-branched 



sporangiophore bearing monosporous sporangia, x 

 130. (After Van Tieghem.) 



131. Pilaira dimidiata : o', mature sporangium, x 120; &, 



a plant with a young sporangium, x 80 ; c, spores, 

 X 500; d, columella, x 120. (After Grove.) 



132. TuhercuUna persicina, section through a surus, x 



120. 



133. Grapliiola phcenicis, section of fungus growing on a ^ 



leaf oi Phoenix dadylifera ; a, sterile tuft of hyphse 

 that spring from the base of the hymenium after the 

 spores are formed, x 200. 



