12 
WARD’S NATURAL SCIENCE BULLETIN. 
Some Variations of Birds and Mammals. 
It is necessary for the young naturalist, seek- 
ing to acquire a knowledge of the many species 
of animals, to obtain a general idea of the kind 
and extent of variations to be met with in the 
same species, and to appreciate the distinctions 
between varieties of a species and separate 
species. 
Laboring under the impression that these facts 
need popularizing for the many who persue the 
walks of science merely as a pastime, and who 
disclaim any particular research in this line, we 
will attempt to present the principal variations 
that are to be recognized. 
The chief of these to be met with are classed as 
sexual, those dependent on age, seasonal, indivi- 
dual, geographical and climatical. The first 
being familiar to all, or rather, as all are ac- 
quainted with its existance, does not come 
within the object of this article, which is simply 
to point out the less familiar variations, and on 
what they are dependent. We will simply state 
that in most cases the female is of smaller size 
than the male and less pleasing in appearance. 
Among mammals she is more cowardly — unless 
in charge of young; among birds her song is in- 
comparable with that of her mate. 
Variations dependent on age are difficult to 
characterize in a few words ; in fact, so diversi- 
fied are they that many naturalists have been led 
astray by them, naming as new species animals 
that upon closer study proved to be but the im- 
mature forms of already recognized species. 
Some birds are actually larger when young than 
when adult. The plumage is generally more or 
less spotted in the immature and, irrespective of 
sex, is for a time almost identical with that of the 
female. Parts that are white in the adult are 
washed with a brownish tinge that gradually 
gives way to pure white. We know of no case 
where the immature mammal is larger than the 
adult, the variations usually consisting of a dis- 
proportion of parts, changes of dentition, varia- 
tions in general color and an inclination towards 
spots and stripes. 
Seasonal variations include those of the breed- 
ing season and others that are related to climate. 
Of the former we have such cases as the “ keel” 
on the pelican’s bill and various wattles or excre- 
scences that appear or become greatly dilated at 
this period, the appearance of plumes on herons, 
egrets, etc. , the development of spurs on the wings 
of some birds and also the song of birds. In 
mammals, the shedding of antlers in the different 
deer and the various odors given off by the male 
of deer, elephants, various rodents and other 
mammals are related to the breeding season. 
Among the more pecnliar seasonal changes are 
the change of color in the bill and feathers of 
some birds, the shedding of the margins of 
the feathers producing a like change in coloration 
and the changes brought about by the one or 
more moults — such as the male Mallard, Anas 
boschas, wearing the female plumage for three 
months after the breeding season. 
In winter many animals change their color in 
a marked degree many becoming entirely white — 
while of those that do not go to this extreme, a 
large number, principally birds, have a distinct 
summer and winter coloration. 
The next, individual variation, is a subject 
which we feel sure is very generally underesti- 
mated by the popular reader. The idea seems to 
be prevalent that all animals of a certain species 
must be exactly alike, an idea that is very 
erroneous. 
Let us first cite the case of the domestic pigeon 
Gohimba lima — variety domestica. There are 
about a hundred and fifty kinds of domestic 
pigeons artificially developed from the same 
original stock. Many kinds of rare variations 
are here displayed in the number and shape of 
the wing and tail feathers, in the formation of 
the skull, proportion and shape of bill, naked 
space around bill and eyes, proportion and shape 
of legs and feet and also in the number of sacral 
vertebrae. In fact there is as much difference 
between the various breeds of this one species as 
there is between many genera. The various 
breeds of dog, from the Pug to the Grey Hound, 
are supposed to have all originated from the 
same species and consequently to be specifically 
united. 
But these variations are artificial— the result of 
selective breeding, and have not their parallel in 
undomesticated animals. However, no two 
animals are exactly alike. There is always a slight 
individual variation; which, omitting malfor- 
mations, is at times quite appreciable. Upon 
some of these isolated cases new varieties and 
even new r species have been founded— species (?) 
which have never but once been observed. No 
extensive series of skulls of any one kind of 
animal can be examined without showing a con- 
siderable difference between some of them in 
regard to general outline, specialization of parts, 
number of teeth, etc. The proportion of differ- 
ent parts vary much in some specimens. In 
birds the number of wing and tail feathers is by 
no means as constant as supposed by some. 
Individual variations can generally be recog- 
nized as such because they follow no law of 
geographical or climate variation; seeming rather 
to be purely accidental. Still it is probably im- 
possible to thoroughly separate these kinds. 
For instance, a bird may be born of southern 
parents inheriting their peculiarities; yet it is 
not improbable that it may take a northern mate, 
migrate with it to a northern breeding place, 
thus making one liable to mistake a purely geo- 
graphical for an individual variation. 
The general laws of geographic and climate 
variations may be given as follows. 
From the high latitudes towards' the equator 
a gradual diminution in size takes place. 
Towards the quator there is, among many birds, 
an increase in the size of the bill and tail, not 
only relatively but absolutely; this is all notice- 
able in birds from the Mississippi Valley. 
Toward the equator there is a very noticeable 
darkening and intensifying of color in birds and 
mammals. In the regions of perpetual snow and 
ice, everything tends toward albinism while 
nowhere is such brilliancy of color noticeable as 
in the tropics. From the East towards the West, 
the same thing is perceived, birds and mammals 
being brighter in the central than in the Atlantic 
States. As a general rule the more humid the 
climate the deeper and brighter the colors. All 
are familiar with the bleached appearance of 
birds and mammals from the arid plains of the 
West, and the African deserts, and with the 
vivid coloration displayed by those from the 
damp jungles of the tropics. Animals are less 
energetic in the warmer climates, and birds 
are not so much given to song in the tropics; 
most of them uttering only harsh discordant cries. 
A familiar example is that of the Bobolink, 
Dolichonyx oryziwrus, a superb songster in north- 
ern localities, a disagreeable screamer in the 
South. The same may he said of the Brown 
Thrasher, Harporhynchus rufus , and many other 
species. 
Now that we have touched upon the most ob- 
vious variations that are to be met with in birds 
and mammals from different localities, let us 
briefly consider the effect that they have upon 
the nomenclature. 
As long as two groups of animals present dif- 
ferences enough to be recognized as distinct, and 
are not connected by a series of intermediate 
forms shading insensibly from one to the other, 
there is no hesitancy in giving each group a bino- 
mial name; thereby recognizing them as two 
separate species. 
When, however, they are connected by a series 
of intermediate forms, these varieties have a third 
term added, making each a trinomial. In this 
manner a specimen may be a variety of a certain 
species and still be farther separated from it than 
are two distinct species; so then the test of the 
validity of a specimen to specific distinction 
must be the absence of the intermediate forms 
through which it has passed in arriving at its 
present state. For example, there are four varie- 
ties of the Screech Owl, Scops asio. If in time 
the intermediate forms between any two of these 
varieties were to become eliminated, then the 
one of these varieties farthest from the original 
Scops asio would be regarded as a separate species, 
and the next removed as a variety of this new 
species. 
Just how far this can be practically carried out, 
where the line can be drawn between what we 
may designate the very various varieties, re- 
mains to be seen. It has already gone so far that 
descriptions cease to describe the gradations in a 
satisfactory manner, and one can easily see how 
this might be carried to such an extent that no 
one but the describer would know what was 
meant. 
We hope that the good sense of our naturalists 
will carry us safely over this difficulty and keep 
them from sacrificing science for a love of words 
and hair-splitting distinctions. jj l yy 
RARE SPECIMENS. 
The Natural Science Establishment has lately 
obtained several species of mammals and birds 
which are rarely seen outside the larger museums 
of Europe. From South America we have three 
peculiar rodent forms, the Mara (Dolichotis pata- 
gonica), the Viscaclia ( Lagostomus trichodactylus) 
and the Chinchilla (Eryomys chinchilla). The first 
of these, an inhabitant of the barren plains of 
Patagonia and Southern Argentine Republic, is 
particularly difficult of acquisition. 
Besides these, we have in alcohol specimens of 
the young Chimpanzee and Belideus bidens, the 
latter with foetuses. We have also skins and 
skeletons of Ursus arctos and skeletons of Gazella 
arahica, the Blesbock ( Damalis albifrons) Canis 
azarca, the Black Leopard (Felis leopardus rar. 
melas ), and Auchenia Guanaco, besides skins of 
Didelphys azarce and Dendrocygna viduata. 
MODELS OF RHIZOPODS. 
We would call the attention of those who are in- 
terested in the lower invertebrates and in the dis- 
semination of knowledge concerning these little 
creatures, to our acquisition of models of twelve 
typical recent Rhizopods. Some of the genera 
represented are Amoeba, Euglypha, Lecquereusia, 
Pamphagus, Trinema , Difflugia, Pseudodifflxigia 
and HyalospJienia. The models of Amoeba are 
manikins, clastic so as to display the internal 
structure. This and all the other models are 
careful copies of nature both in form and color. 
One of the most interesting of the twelve genera 
is Difflugia. The developing shell of this Rhizo- 
pod is strengthened by a crust of minute pebbles. 
This is admirably represented in the models. 
The price of a set of these twelve types is $20. 
> ■» 
Entomological Notes. 
Observing a colony of the common red ant 
( Formica sanguinea ) busily collecting the nectar- 
ine fluid from their little cows, the aphides, I 
was curious to know whether the plant with its 
herds of these small insects was the property of 
one colony of ants or whether several colonies 
run this honey-mine “on shares.” To dispel all 
my doubts on the subject, I procured ants from 
another colony and placed them near the aphides. 
The new comers immediately went forward and, 
caressing the patient plant lice with their anten- 
nae, imbibed the “forbidden sweets.” They 
were soon observed, fiercely attacked and com- 
pelled to abandon the sugar plantation. Succes- 
sive experiments fully proved the fact, that at 
least small plants and their aphid parasites are 
the sole property of but one colony of ants. 
At another time I placed a small black ant in a 
colony of the red ant. Instead of running about, 
the new comer stood quietly, touching with its 
pointed abdomen whatever came in contact with 
it. I further observed that all ants thus touched 
seemed partially paralyzed. A large black ant 
then made its appearance and preyed upon the 
red species. In its course it happened on the 
small black ant and judging, no doubt, that its 
dark color could not effect the sweetness of the 
morsel, grasped the wee creature but let it drop im- 
mediately and crawled away slowdy, as if in pain. 
The limbs on one side of its body seemed para- 
lized. I should be grateful if some reader of the 
Bulletin, whose observations in Entomology 
are more extended than my own, would give me, 
if possible, the name of the small black species 
and further information respecting its powers of 
paralizing its adversaries. N. R. Wood. 
