332 The Botanical Gazette. [August, 
ring of the clinostat has acted as a repeated stimulus, thus - 
exhausting the power of response). The Cuscuta is placed 
in the limited category of twining plants which have the 
power of irrito-contractility. The comparison of its phenom- 
ena of this character, with those exhibited by tendrils are not 
always happily made, while throughout the paper the author 
seriously confuses climbing and twining plants. 
Cuscuta is not markedly hydrotropic and exhibits only a 
weak heliotropism. The latter power is not in any way cor- 
related with the amount of chlorophyll present, which varies 
inversely with the amount of nutriment received from the 
ost. The high development of the power of movement and 
special senses of this parasite renders it a formidable enemy 
to succulent plants, whose only means of defense against it 
are firmness of cortex, size, and the possession of poisonous 
juices. 
In places the article calls for the closest scrutiny of the 
context to bring out the meaning. The large mass of detail 
presented makes this obscurity in part unavoidable. —D. T. 
Mac DOUGAL. 
