BOTANICAL GAZETTE. 147 
Another obvious objection may be raised as follows :—The 
Saprolegnie are in the main saprophytes, and yet they are said 
to be advanced towards apogamy—parthenogenetic, at any rate. 
The answer may be that they are saprophytic chiefly on animal 
protoplasm, which contains more potential energy than does 
vegetable protoplasm. At the same time, some Saprolegni are 
or yeag on plants, and S. ferax now appears to be parasitic on 
sh’. 
I may say, in conclusion, that it was during the study of the 
parasitic fungus of the coffee disease (Hemileia vastatrix)’ in Cey- 
Jon that I was first led to speculate on the enormous amount of 
energy displayed by an organism which shows not the remotest 
satisfactory trace of sexuality, but which reproduces itself through 
many generations exclusively by means of asexual spores. at 
this energy of reproduction is derived from the coffee tree there 
can be no doubt, and that it is at the cost of the reproduction of 
the host is sadly evident; the clear inference from the fact that 
the coffee leaf supplies substance for the reproduction, ete., of a 
fungus at the expense of its own fruit, is that the fungus takes 
matters which are very rich in energy, so rich, indeed, that the 
ungus is not necessitated to sort these substances in special re- 
productive organs, aud to secrete sexual elements, one of which 
would then reinvigorate the other, but may employ them forth- 
with for the purposes of its own relatively simpler existence and 
reproduction — Quart. Jour. Mie. Se , April, 1884. 
er 
GENERAL NOTES. 
Polarity of Lettuce Leaves.—The orientation of the leaves of Lactuca 
Scuriola, which has made it one of the two best known “compass” plants, i 
Peated in a less degree in the leaves of the common garden lettuce. The polar- 
ity is Searcely apparent until the lettuce begins to throw up the flowering _ 
: 18 very weak in the curled and wrinkled varieties, but it is well marked in 
® Cos varieties, which have flat narrow leaves much like the wild L. Scariola. 
The observation was made on over one hundred varieties of lettuce grown the 
Present season in the garden of the New York Agricultural Experiment Sta- 
moa—J. ©. A. 
oe Moscheutos and H. roseus.— Dr. J. Guillaud, of Bordeaux, 
* pamphlet containing his investigations resulting in the identification of 
.." Prof. Huxley. « ic. Se’., 1882. [It may be found upon other- 
Seong 2s Giceealet empresa ma of Mr. George Marray. 
og ’ .— a ; 
July, eae sour Mie. he Jan, 1882; noticed and figured in ‘Am. Nat’, 
7 
* 
