xvii.] CLUB-ROOT OF TURNIPS, CABBAGES, ETC. 101 



resting state in affected turnips all through the winter ; 

 and in the spring, if another transparent slice is taken 

 from a small club formed during the previous year, the 



X-IOOO 



FIG. 38. CLUB- ROOT DISEASE OF TURNIPS. 



Small spores of PlasmodiopTiora, Brassicw, "Wor., and single Resting-spore 

 of Peronospora parasitica, Pers. Enlarged 1000 diameters. 



spores will be found perfectly ripe and ready for germi- 

 nation. This germination takes place as illustrated in 



FIG. 39. CLUB-ROOT DISEASE OF TURNIPS. 



Spores of PlasmodiopJiora Brassicce, Wor., germinating and producing 

 Amoeba-like zoospores. 



the six spores, enlarged 1000 diameters, and numbered 

 from 1 to 6 on Fig. 39. The cell wall of the spore 



