560 ZOOLOGY. 
“ protective,” — the paler tints developed in dry regions better 
harmonizing with the pale gray tints of the vegetation at such 
localities, — yet the transition was as gradual over the intervening 
districts as were the climatic changes themselves over the same 
areas; while it was claimed that evidence of the direct influence 
of dry heated winds upon color was abundant; and that the 
gradual transition between diverse forms was so uniform and 
general that it pointed to constant and general laws of geograph- 
ical variation. When the known transitional stages between | 
formerly supposed specific forms were exceptional, it was more 
or less common to regard them as the result of hybridization, but : 
the gradual, almost imperceptible, stages of transition between — | 
well-marked forms differently situated in respect to latitude ren- 
dered such a theory now highly untenable, and scarcely pes 
probable as applied to intergrading forms occupying localities 
widely separated in respect to longitude. In regard to species as 
distinguished from varieties, it was deemed proper to regard as 
species such groups of individuals as did not at present intergrade, 
and as varieties such groups of individuals, though more or less 
diverse in their extreme phases, as were found to thoroughly inter- 
grade, — which, he remarked, is only what many and probably the 
majority of naturalists are practically doing. 
Nore on tHe Tureap Worm (filaria anhinge) FouxD IN THE 
arkable par- 
Brarn or tHE SNake Brrp. — An account of this remarss” 7 
asite was given in the *“ Proceedings of the Boston Society 9 
Natural History ” Oct. 7th, 1868, showing that it was present z 
seventeen out of nineteen birds examined, and always one 
the same place, viz., the space between the cerebral lobes : 
cerebellum. It was also shown that these worms arè "URT 5 
their oviducts containing eggs in all stages of developmen ood 
the egg just formed to the mature enibryo. In the lower porti : 
of the oviduct the young were hatched and : 
During the last i when in Florida, I had an ope 
through the kindness of my friend G. A. Peabody, Esq», T i 
ining ten additional birds. The proportion of the infec 
was less than in the previous examinations, nO worms being of 
in four. Two of these were not mature birds, but of soa w w 
the other two I have no record. Of the six in KERS "i ae 7 
while two had Ov 
i ao AE 
ready for exclusion. 
found, four had both male and female Filariz, 
