Dept.] 
NATURAL SCIENCES OF PHILADELPHIA. 
9 
Dr. Hammond described a canine monstrosity obtained by him at Fort Riley, 
Kansas, in which, besides the presence of six legs and several supernumerary 
toes, there was an entire absence of intestines and anus, the stomach ending 
in a cul de sac. 
Dr. Atlee said, that he had, in his paper, said nothing of the causes of mon- 
strosities, they being, in fact, altogether unknown. Only three modes of 
causation appear to be possible : 1. Defect in the germ ; 2. Emotion, such as 
fright, &c, in the mother ; 3. Accidental violence acting upon the foetus during 
gestation. In regard to neither of these can we obtain, at present, accurate 
knowledge. 
Dr. CoKSE observed, that some modifying causes are occasionally obvious ; 
as, irregular contractions of the uterus, such as are known to occur, and which, 
by pressure, may act upon the foetus. Dr. Corse possesses a specimen which 
illustrates this ; in which there is no neck, and only a vesicle in place of the 
brain. In many cases of acephalous monstrosity, Dr. Corse would suppose ex- 
ternal causes to be most probable. 
Dr. Leidy thought it difficult to conceive how external causes could act upon 
the embryo at so early a stage, and while so minute as it must be at the time 
when such a deformity is produced. Dr. Leidy alluded to the experiments of 
Newport upon the fecundation of the frog, as suggesting the possibility that 
the defect might occur, in connection with the act of conception itself. 
March 15th. Dr. S. W. Mitchell read a paper, entitled " Observations on the 
Blood of the Sturgeon,^^ illustrated by drawings of crystals obtained from the 
albuminoid corpuscles of that fish ; and containing, amongst other interesting 
points, new reasons for the belief, that Lehmann's opinion of the coloring mat- 
ter of the blood being essential to the constitution of blood-crystals, is erro- 
neous. 
Dr. Mitchell further remarked, upon his having noticed, with surprise, that, 
when a drop of sturgeon's blood was left at rest until its edges began to dry, 
the nuclei of its corpuscles, which are easily seen, approached one another ; 
so that, if there were several corpuscles, their nuclei would seem to be in 
contact. The phenomenon resembled, somewhat, the nummulation of the 
corpuscles, at the beginning of an inflammation. Tlie mere drying up of the 
corpuscles did not explain this ; the explanation was not obvious. 
Dr. H. Hartshorne inquired, whether ordinary gravitative attraction might 
not explain it, as it does the approaching of light particles floating in a liquid 
to each other, or to the sides of the vessel ? 
Dr. Mitchell thought not ; doubting, even, whether the latter phenomena 
were explicable by gravitative attraction alone. 
Dr. Hammond called attention to the fact, mentioned in Dr. Mitchell's paper, 
that he had not succeeded in obtaining blood-crystals from the fresh blood of 
the human finger. Dr. Hammond had made the attempt with blood of the 
soft-shelled turtle (Trionyx) ; during the first week he could find no crystals : 
but, two months' afterwards, they were distinctly observable. 
Dr. Mitchell had repeatedly failed in the attempt with blood of the water- 
turtles of the vicinity of Philadelphia. He had, however, in such experi- 
ments, observed certain saline crystals, which did not undergo granulation 
and fibrillation before solution ; which Dr .M. believes to be a test. 
Dr. Morris considered, nevertheless, that the crystals, mentioned by Dr. 
Hammond, were true blood-crystals ; being, as he himself had witnessed, 
witliin the blood-corpuscles. 
Dr. Leidy remembered having once seen a similar occurrence in the blood of 
a salamander. He had, also, noticed octohedral crystals within the epithelial' 
cells of a lepidopterous insect, the Arctia Isabella; which is a caterpillar, 
found in winter under stones and leaves : each nucleus of an epithelial cell 
was the centre of an octohedron. 
1858.] 
