692 ZOOLOGY. 
the same grounds we must reject all characters now regarded as 
generic, for there is scarcely one which cannot be found to be va- 
riable in some species in some more or less remote region of the 
animal kingdom, recent or extinct. Hence, as I have often urged, 
it is the constancy of a character in the group of species where it 
exists that determines its value. This is the philosophy of uni- 
versal custom. The same remarks may apply to my Orconectes 
inermis. Though I could not make it agree with Dr. Hagen’s sec- 
ond form of O. pellucidus, it may be such, as Dr. Hagen’s knowledge 
of these animals is much greater than mine, and I would at once 
accept his determination in the case. But what are these “forms”? 
If inconstant they are only varieties ; if constant, species. — EDWARD 
D. Core. 
Viratrry AND Sex.— Prof. Riley mentioned at the meeting of 
the American Association a few interesfing entomological facts in 
support of Dr. Hartshorne’s paper, and to show that in some way 
or other the male element is connected with defective vitality. In 
studying Phylloxera vastatria, or the grape-root louse, he had al- 
ways found the male pupæ most abundant on such roots as had 
been most depleted and where the insects were already beginning 
to die off for want of sufficient nutrition. 
In the common oeyster-shell bark-louse of the apple tree (My- 
tilaspis conchiformis), whith had been increasing and spreading for 
many years past in the northwestern states, something similar 
occurred. The male of this species had been sought in vain for à 
quarter of a century both by entomologists and horticulturists ; and 
they were forced to the conclusion that the species multiplied 
agamically and despaired of ever finding the male. But for the 
past three or four years this insect has been rapidly dying out m 
those sections where it once flourished, until at last it is no longe! 
dreaded by the orchardist. Under these conditions of peng 
vitality the male element suddenly appears, and Mr. Riley h 
the satisfaction of discovering it the present summer. 
the NATU- 
tt Sprxe-HORNED MULEDEER.” —In the July number of 
f a spike- 
raist, Prof. E. D. Cope refers to a supposed specimen 0 
horned muledeer (Cervus macrotis) obtained in Kansas. 
questioning the probable occurrence of ‘* spike-horns” 1 C. "a 
tis, the size of the horns mentioned by Prof. Cope seems to Sa 
the reference of the specimen in question to C. macrotis somew 
Without 
pT Ale Say SAN Oak OAS Pepe Sy Ah Sem ag) tn hy ST 
