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THE AMERICAN NATURALIST [Vol. XL VIII 



An explanation of this peculiar development was sought 

 in a possible attack on the part of cither fungi or bacteria 

 or in soil conditions. But the latter were uniform for the 

 entire flat. Neither fungi nor bacteria could be demon- 

 strated nor did the underground portion of the "ab- 

 normal" plants look unhealthy or underdeveloped. 



At this stage the flat presented the appearance shown 

 in Fig. 1. At the time but three types were distinguished, 

 the first of these constituted by plants which showed an 

 incision of the blade, the second composed of those which 

 apparently had entire leaves, and a third, comprising the 

 small and linear-leaved rosets which, because of the spider- 

 like appearance of the latter, has been designated xCap- 

 sella Bursa-pastoris arachnoidea. There also appeared a 



