1 6 British Fttno^i. 



e> 



granular portion remains and does not escape on 

 cutting. Placing tlie whole fungus in alcoliol or 

 methylated spirit for some time produces the same 

 effect. If sections thus prepared are stained with a 

 solution of eosin, to which a drop or two of acetic acid 

 has been added, the granular contents of the latici- 

 ferous hj]3ha3 become deeply stained. 



Nuclei have for some time past been proved to be 

 present in the cells of fungi, but until quite recently 

 this proof depended mainly on the fact that nuclei 

 become more deeply stained than the remainder of 

 the protoplasm, and so in the case of the vegeta- 

 tive portions of fungi, where the nuclei are minute 

 and not possessed of any very pronounced morpho- 

 logical features, this evidence was scarcely satisfactory, 

 because minute coagulations of protoplasm often 

 become deeply stained, and are thus liable to be 

 mistaken for nuclei. Recently, however, Wager has 

 shown^ that numerous nuclei are present in both vege- 

 tative and reproductive parts of a minute fungus, 

 called Peronospora loarasitica, very common as a 

 parasite in the tissues of various cruciferous plants. 

 In addition to the evidence afforded by staining, the 

 author has shown that the nuclei divide by a process 

 of karyokinesis, in a manner comparable to what 

 takes place in the division of the nucleus in flowering 

 plants. The following process was found to furnish the 

 best preparations for observing the presence and 

 various phases of division of the nuclei. The fresh 

 tissues of the Shepherd's Purse infected with the 



* Observations on the structure of the nuclei in Peronosjjora 

 parasitica, &c. Ann. Bot. vol. iv. pp. 126-14:7 ; pi. 1. 



