234 
SCIENCE. 
nutritive material was bought at 44 cents per pound. The 
cost of the nutritive material in one sample of halibut was 
57 cents, and in the other $1.45 per pound, though both 
were purchased in the same place at the same price — 15 
cents per pound, gross weight. In closing, Professor At- 
water referred to the widespread but unfounded notion that 
fish is particularly valuable for brain food on account of its 
large content of phosphorus. Suffice it to say that there is 
no evidence as yet to prove that the flesh of fish is specially 
richer in phosphorus than other meats are, and that, even 
if it were so, there is no proof that it would be on that ac- 
count more valuable for brain food. The question of the 
nourishment of the brain and the sources of intellectual 
energy are too abstruse for speedy solution in the present 
condition of our knowledge. 
ANATOMY OF THE TONGUE IN SNAKES AND 
OTHER REPTILES, AND IN BIRDS.* 
By Dr. C. S. Minot. 
The tongue arises as a protuberance on the floor of the 
mouth, which in the course of development acquires a mus- 
cular system ; the latter appears first in the reptiles. The 
principal muscles are the longitudinal arising from the hyoid 
bones, morphologically a part of the branchial muscles. In 
the crocodiles these are the only muscles found. In the 
snakes, however, proper lingual muscles play an important 
part, there being a distinct vertical muscle between the 
Ceratoglossi, three distinct transverse muscles, one superior 
and two inferior, and finally a longitudinal muscle immedi- 
ately under the upper surface of the free portion of the 
tongue. Each muscle is distinct and separate throughout 
its whole course ; they can all be traced with facility. The 
disposition of the nerves and other parts of the tongue was 
also described. The examination of the tongue of an Ameiva , 
the common long-tail lizard, revealed a structure in all its 
features identical with that of the snake’s tongue. This 
offers a confirmation of the view that lizards and snakes are 
closely related, for in no other class of reptiles has a snake- 
like tongue been observed. On the other hand, the tongue 
of the Charmeleon is peculiar. It has been previously 
studied by several authors, all of whom have committed 
important errors. The whole tongue is exceedingly com- 
plicated and difficult to understand. The arrangement of 
the muscles is the most remarkable yet observed among 
animals, and they cannot be homologized with the muscles of 
the tongue of any other animal, until our knowledge of the 
subject shall be greatly enlarged. Dr. Minot stated, while 
he had made new observations on the tongue of the cha- 
masleon, that he had been led to recognize more clearly, 
than previous writers, the difficulty of explaining the me- 
chanism of the organ. The tongue of birds presents a uni- 
form type, distinct from that of any reptile. The tongue 
has its simplest and lowest form in the crocodiles, is much 
advanced in the snake and fissilingual lizards, remarkably 
transformed in the chamaeleon, and presents a special type 
in birds. These points are brought out by numerous mi- 
croscopical observations on the nerves, blood vessels and 
other parts. 
SOME FACTS AND THEORIES BEARING A 
RELATION TO THE DISTRIBUTION OF 
ORGANIC FORMS ON THE GLOBE.f 
By W. H. Davis. 
The author commenced by pointing out the fact that the 
inorganic conditions which surround us are in a state of 
change, ceaseless, and ever varying ; and illustrated tnis 
portion of the subject by references to denudation and re- 
deposition of existing land surfaces. It was then shown 
that these inorganic changes could not take place without 
at the same time producing an effect on the organic world 
commensurate in some degree with the intensity of the inor- 
ganic change ; this led up to the question of the same area 
of the earth’s surface at successive periods possessing a 
varying fauna and flora, and the light thrown by palaeonto- 
logical investigation upon the changes of land surface that 
* Read before the A. A. A. S., Boston, 1880. 
\ Read before the Metropolitan Scientific Association, London, 
England, Oct. 12, 1880. 
had taken place, and this knowledge of past conditions in 
its turn throwing an instructive light upon the former range 
of the various orders and genera of organic beings. Thus 
it was, that as there was a perpetual ebb and flow and cease- 
less interchange of inorganic structure, so the forms and 
types of life affected by these influences are also in a con- 
tinual and corresponding state of unrest, from the nec- 
essity of the two conditions being in harmony with each 
other, the organic and the inorganic. 
The first problem, therefore, was, seeing that a change of 
the organism was necessitated by a variation in the condi- 
tions of existence, whether these changed conditions as they 
arise were of themselves capable of inducing structural 
differences in organized forms subjected to their influences. 
Starting with the negative view, it was pointed out that 
there were but two courses open to the organism affected — 
migration or extinction : but the former cause of itself in- 
volved a minor change of conditions, and as in the life his- 
tory of the earth, a second, third, or greater number of 
migrations were necessitated, at last the probabilities were 
of the environment of the organism being so varied from 
its primary condition that extinction in this case must also 
ensue. Thus a form persisting through several or many 
periods of geological time would be impossible ; but as 
this was contrary to many observed facts, the converse 
view was discussed, and actual structural modifications due 
to changed conditions referred to, as in the case of animals 
and plants introduced into West Africa, South America, 
and other regions. Mimicry was also instanced as evidence 
of the influence of inorganic form on living organisms. 
In man the Europeo-American nation of the United States 
was quoted as an instance of a race being formed under 
our very eyes. 
It may, of course, be urged that the differences here 
pointed out are only of a character such as might be 
anticipated to have arisen, and that, pendulum-like, they 
vibrate through a very small arc, and in no way give rise to 
fresh species, still less to fresh genera. The next point, 
therefore, that comes in for consideration is whether these 
structural differences are ever commutative. We have seen 
that the change which can be produced in a single species 
is not an alteration in respect of one character only, but 
an alteration of many characters affecting different parts 
and portions of the same organism. Now these modifica- 
tions, small as they are (in comparison with the question of 
a complete change of species), certainly did not leap into 
being in an instant, but have exhibited themselves grad- 
ually. Here, then, is a starting-point for the cumulative 
evidence. The changes themselves, even so far as they 
have gone at present, are but expressed cumulative results, 
and having become once established, it is only in accord- 
ance with what we have already seen to be the case, that 
with a further change of surroundings, a corresponding 
modification must ensue, or extinction alone must follow. 
But in this argument we are not altogether left to the evi- 
dence as visible to the eyes of mankind during the historic 
period, but a mass of the facts of palaeontological history, 
some embryological investigations, and many zoological 
observations are absolutely inexplicable save on these 
grounds. If we trace the connections of the reptilian and 
avian forms, the progressive stages in time of the Equidae, 
or the changes in structure of the more lowly Ammonitidae, 
the same answers must be given, that the extremes observed 
in the respective groups have been the result of a cumula- 
tive modification due to the types of life being in a condi- 
tion of instability, and ever seeking to bring themselves into 
harmony with their inorganic surroundings. 
In further illustration of this portion of the subject, sym- 
pathetic modification or correlative adaptation may be noted, 
as when the change of one structure in an animal induces 
changes in other structures remote and apparently uncon- 
nected with it, as in the pigeon, the beak and toe lengthen- 
ing and shortening in unison. 
Degeneration was strongly insisted upon as a factor in 
producing fresh types, equally with progressive modifi- 
cation. 
Passing, then, to the various views entertained as to the 
causes of the present geographical distribution of life, the 
doctrine of specific centres was explained, the author main- 
taining that this idea was, in effect, but the old teleological 
argument that every organism was created for a definite 
