100 The Botanical Gazette. 
structure, some on account of the very minute root tipss 
Anemone thalictrotdes and Coptis trifolia; others failed of st 
cess since the material first gathered proved to be poora 
then the ground had become frozen and I was unable too 
tain more material. Among these latter plants, are 7halielr 
polygamum, Anemone Pennsylvanica, Ranunculus recurvats 
Clematis Virginitana, Agquilegia Canadensis and Cah 
palustrts. 
The assigning of the species to the types as I havep 
them may be but provisional, for though I had sections of 
eral root tips from each species in almost all cases, yet som 
times two sections from different roots of the same spe 
did not appear exactly alike in their terminal structure, ai 
study of a greater number of roots might necessitate cial 
ing some plants from one type to another, but they certalt 
do not all fall under one type of structure, + as indicated! 
Erickson. : 
VI. Summary. 
on the basis of the changes taking place through se 
growth. | 
First, those plants which show no marked change of 8 
structure, the primitive radial type of structure per®” 
in the older roots. In this class I include Aaa’ 
acris, R. Pennsylvanicus, R. recurvatus, R. septentr 
R. hispidus, R. fascicularis, R. bulbosus, R. multipan 
circtnatus, R. aquatilis var. trichophyllus, Hepatica 
HT. triloba, Aconitum Noveboracense, Trollius 
Caltha palustris. 
Actea alba, A. spicata var. rubra, Anemone ViPS 
us. 
Third, those plants which show in the older 
*My study has all been upon the mature root. 
