, 1876-11-11

bred at high attitudes or at the North
were thus shown to be smaller than
those of the same kind ut the South or
at lower elevations; Western birds have
longer tails than Eastern ones OF the
same species; the bills increase in size
below certain Mtltuoc; on the Pacific
coast the birds acquire darker hue.
Similar changes in the ears and feet OF
animals, rs well as in their fur, are noted
ms dcpcndent ON climate When these
changes were tnbulatcd and shown on
geographical chart, they were found CO.
incident with variations already asccr-
tanned in the annual amount OF rainfall
in the different regions. The total num-
Der of species OF birds was reduced
abont n fifth by these Investigations;
the number Of species of squirrels di-
mnishcs one.half or more. Doctor a.
S. Packard sees that this process Of re-
ducing species must go on while the gaps
between them are gradually filled, and
the genera must follow in this process
of fobIteration. lie says: "The work of
the systematic biologist amounts to but
little more than putting Nature into a
strait jacket
In producing new evidences for the
doctrine of natural selection, Doctor Burt
G. Wilder has borne a distinguished part
Anatomical changes have been closely
observed. To this class Of students be-
long also the essays OF Doctor VIM. H..
Brooks, Doctor Englemann, and protes-
sor Charles V. Riley. Professor Riley's
proof of the interdcpendence of flower
and insect in the case Of the Yucca moth
is one of these tnumphs. Professor
Grotc has made noteworthy observa
ton on the alterations caused by use or
non-usc in tne untennW Of the butteItly,
one of the most striking instances of the
better knowledge which closer Observa.
tion OF Nature has conferred in the shape
of the honey comb. In the days OF the
Bridgewater Treatiscs it was demonstrate
ed that the form of the cell, mathematic'
ally considered, was that which used
space and material to the greatest posi-
hle advantage. The late Professor jeff
ries Wyman spoiled this pretty.theOry by
showing that celt-of this mathematical
perfection is rarely, if ever, made. The
cells are built uneqnally and in the great
est variety of shapes, due TO incorrect
alignment and many other causes. There
is no geometrical accuracy about the
structure. Following the list Of the cell
making insects, from wasps, hnmblebees
upward, we find that there are all grades
from shapeloss cells to those that ap'
proach but never reach perfection. Pro-
fesSor Wyman showed remarkable ingen-
uity in this research, making plaster
casts of the comb, dissolying out the
comb from The plaster, then cutting sec
tons and taking electrotypes. The late
Professor Chauncey Wright was almost
equally fortunate is showing that the ar
rangement of leaves Of plants along their
axes was due to circumstances of growth,
and not result OF blind law.
Among the examples of the survival OF
forms by aduptiOn to change environ
ment, Professor Morse mentioned the
| discovery by Earnest Ingersoll of marine
mollusks and living saltwater crabs high
up in the Rocky Mountains. Some OF
the crabs were closely related to existing
marine forms. The researches Of Prof
Marsh concerning the siredon, an anima
of the salamandcr kind, that looses itf
gills and becomes, when moved from its
native habitat, one previously recOrueo
under an entirely different genus (ambly
stoma), has been described and figured
in one OF the earlier extras Of the Til
June. Fer many years Professor Agassi'
argued that the blind fish of the Nam
moth Cave were a race created in theil
present condition. This whole matter
has been removed from discussion by the
accurate Investigation and thorough re
searches OF Drs. Packard and i. W. Put
nam and series Of fishes, from thosC
with perfect eyes to those without any
including between them various def
cicncies of vision, has been found in Ame
lean caves and secluded waters. Tht
discoveries of Professors Alpbeus Uyat