638 MINNESOTA BOTANICAL STUDIES. 
tions above the general surface of the spore can be detected, 
there may yet be observed almost the usual appearance when 
the spore is examined in face view. Instead of papille, their 
places seem to be supplied by translucent dots. Now the most 
interesting outcome of this study is the observation that the 
European specimens, while having what are always rated as 
smooth teleutospores, yet show when looked at dry and in face 
view, the same appearance of translucent dots and in the same 
abundance and distribution as do American specimens. The 
American form, therefore, simply accentuates characters that 
are primitive in the trans-Atlantic form. 
The uredospores also have interesting, but less significant, 
characters showing variability. As a rule they do not much 
exceed in size those from European specimens, although the 
tendency toward largeness is apparent. But in many American 
specimens the walls are greatly thickened (compare uredospores 
in Figs. 5 and 7), and give a striking appearance under the 
microscope. These thick-walled uredospores are sometimes 
small, and sometimes large. They occur on various species of 
violets and range from the Atlantic coast to the Pacific. Fine 
illustrations are found in material on Vola primulefola col- 
lected at Isle au Haut, Me. (Fig. 8), the uredospores being 
small, and on Viola glabella collected at Bingen, Wash. (Fig. 
7), the uredospores being large. After all, the form is only oc- 
casionally met with. If it is an adaptation to some particular 
environment, it is difficult to see what that may be. The form 
on Viola primulefolia from Maine was collected within a few 
hundred feet of the open ocean among rocks, yet in the same 
situation and intermixed grew Vzola lanceolata with rust show- 
ing uredospores having almost normally thin walls. 
It is possible that these interesting variations belong in some 
way to obscure species, but our study has shown no morpho- 
logical boundaries. It is more likely that they indicate races, 
or possibly so-called biological species. A well-directed series 
of cultures would undoubtedly yield important results. 
A few words regarding the American synonymy may be 
helpful. Cooke described Puccinza hastate in the third volume 
of Grevilica from material collected in Maine by E. C. Bolles. 
The host was Viola hastata. The uredo and teleuto stages are 
described, but the only distinctive characters are the measure- 
-ments which are given as 20-22 y for the uredospores, and 
