OH. xxxvii.] PARASITIC FUNGI. 331 



Street London. Engravings from the same transparent slice 

 were published by us, with a description, in the Gardeners' 

 Chronicle for 20th October 1877. Mr. Carruthers also 

 published an extremely small engraving and a brief de- 

 scription of the fungus in his printed address, read before 

 the Geologists' Association in 1876. We have named 

 this parasite Peronosporites antiquarius, W.Sm. To us 

 the mycelium appears to be distinctly septate, and the 

 large globular oogonia or zoosporangia appear to show clear 

 traces of zoospores within their walls. 



Mr. J. T. Young, F.G.S., the owner of the transparent 

 slice of fossil Lepidodendron, has recently replaced the 

 example in our hands for a new illustration ; and our 

 engraving at Fig. 139, enlarged 400 diameters, has been 

 made direct from the microscope. 



Notwithstanding criticisms to a contrary effect, we have 

 no hesitation in repeating, after a renewed and prolonged 

 examination of the preparation, that traces of zoospores are 

 distinctly visible in many of the oogonia ; there is no reason 

 why they should not exist, but good reason why they 

 should ; the mycelium is septate ; and the oogonia, as in 

 all Permosporew and Saprolegniece, are cut off from the sup- 

 porting threads by distinct septa. The slice of Lepidoden- 

 dron from which our illustration is taken has a large 

 number of free oogonia in different parts of the silicified 

 tissue ; such free oogonia or zoosporangia are very com- 

 monly seen in Peronospora, as in P. ganglioniformis, B. 

 The zoospores in some of these free isolated examples are 

 much more distinct than in the characteristic group, en- 

 graved to show the oogonia only, in Fig. 139. The 

 traces of zoospores, seen in Peronosporites, exactly agree in 

 size with the zoospores of Peronospora infestans, Mont., 

 Figs. 128 and 136. The genus Peronospora is in close 

 and obvious relationship to the Saprolegniece, one member 

 of which, Saprolegnia ferax, Kutz., is the cause of the 

 salmon disease. Professor de Bary has even said that 

 facts do not exclude the possibility of the fungus of the 



