279 
such comparatively recent introductions as Akedia guinata, Acti- 
nidia polygama, Solanum muricatum, etc. It is not only the best, 
but, I may say, the only work descriptive of our domesticated 
flora. It will be heartily welcome by the many who have neither 
time nor facilities for the pure study of systematic botany, but 
who, nevertheless, love flowers and takes an intelligent interest in 
the wealth of decorative and useful plants which surround them on 
on ail sides. VA, 
Phlanzenkrankheiten durch kryptogamen Parasiten verursacht 
Karl Freiherr von Tubeuf. Berlin, 1895. 
This book is a condensed treatise on plant “parasitism” or 
“symbiosis” in its widest sense. Unfortunately the term plant- 
disease (Pflanzenkrankheit) is not defined, but the reader is led to 
assume that any change produced in a plant due to a “symbiotic” 
or “parasitic” relation with another plant is considered a plant 
disease. 
The attempt is made to treat the physiological and morpho- 
logical relations of parasitism from a comparative standpoint. 
Physiological and anatomical details are not entered into as that 
would be both impossible and unnecessary because of the copious 
citations of special authors whom the specialist interested may 
consult. All the authorites quoted are recent and standard. With 
few exceptions the figures are excellent. The numerous photo- 
graphs are especially interesting. 
The student of general botany will no doubt find Part I. the 
most interesting. Here the author has very briefly outlined his 
conception of parasitism in the wider sense. Here he also shows 
his greatest originality. Especially interesting are his distinctions 
between Mutualism (“Mutualismus”) and Nutricism (‘ Nutri- 
cismus”). By the former is meant that form of parasitism in which 
the two symbionts mutually benefit each other. As the most im- 
portant examples are to be mentioned the lichens. Here two or- 
ganisms, an alga and a fungus live together for mutual benefit. 
He emphasizes the fact that this symbiosis has so changed the 
life history of the two organisms that they combine to form a mew 
organism. This union of two originally distinct organisms to 
form an independent organism he designates “individualism.” By 
nutricism is meant that form of parasitism in which one of the 
