240 _ Sctentific jIntelligence. 
Ill. Zoouoey. 
Fresh-water Rhizopods of North America; by Josmru 
Lerpy, M.D., Prof. Anat. Univ. Pennsylvania. 324 pp. 4to., with 
48 colored plates. Washington, 1879. Vol. xii of the Reports of 
the U. 8. Geological Survey of the Territories, F, V. Hayden, 
Geologist-in-Charge: Department of the Interior.—This new work, 
by Dr. Leidy, is a very important addition to the quarto series of 
reports connected with the Geological Survey of the Territories 
under Dr. Hayden. It is the result of a vast amount of careful 
microscopic research with regard to the structure, development 
and habits of these lowest forms of animal life over the North 
American Continent; and the numerous plates with crowded 
ored figures are attractive for their beauty, as well as for the 
instruction they impart. 
Dr. Leidy shows in his descriptions and faithful delineations 
i e 
it saved much detention and explanation; and, now, behold, 
offer them the results of that fishing. No fish for the stomach, 
Joblet, observed, ‘some of 
d food 
As Leidy states (p. 5): : 
“The soft mass of protoplasm, or sarcode, forming the essential 
part of all Rhizopods, has no internal cavity like the body-cavity 
of higher animals, neither has it a mouth like the higher Protozoa, 
nor has it stomach or intestine. Without trace of nerve elements, 
and without definite, fixed organs of any kind, internal or exter 
nal, the Rhizopod—simplest of all animals, a mere jelly speck— 
moves about with the apparent purposes of more complex crea: 
tures. It selects and swallows its appropriate food, digests It and 
rejects the insoluble remains. It grows and reproduces its kind. 
It evolves a wonderful variety of distinctive forms, often of the 
utmost beauty; and indeed, it altogether exhibits such marvelous 
attributes, that one is led to ask the question in what consists the 
superiority of animals usually regarded as much higher the 
scale of life.” 
