1144 The American Naturalist. [ December, 
ductory discussion of insect classification. She has divided her work 
into thirty-one chapters, the first five of which deal with the external 
structures of insects and their transformations. Then the orders and 
suborders are taken up in regular sequence, and their characters 
clearly and concisely defined. We are glad to learn that the author 
intends to have these ‘‘ Outlines’’ published in book form for school 
purposes. 
Recent Bulletins.—Mr. F. M. Webster begins his work at the 
Ohio station by a timely discussion of the Wheat, Midge, Diplosis 
tritict (Bulletin, Vol. IV., No. 5, September, 1891). This pest has 
appeared in Central Ohio in considerable numbers. Professor 
F. J. Niswander discusses plant lice in a five-page Bulletin (No.2) 
issued by the Wyoming station in August. In Bulletin No 3 of the 
New Mexico station Professor C. H. Tyler Townsend discusses a num- 
ber of fruit insects. In the report of the Maine station for 1890 
Professor F. L. Harvey gives a popular account of a number of injuri- 
ous insects which have attracted attention during the year. 
Professor J. B. Smith’s account of his year’s work in the 1890 report 
the New Jersey station contains many results of great practical value. 




- 
MICROSCOPY.! 
Methods of Preserving Human Embryos.—It frequently 
happens that human embryos which come into my possession are almost 
ruined by the physician’s carelessness in preserving the material. For 
instance, I have obtained specimens simply placed in water, a solution 
of policylic acid, strong alcohol, or simply packed in cotton or even 
forced into a small bottle. Any of these methods almost totally spoil 
the specimen for careful study. 
An abundance of material comes into the hands of the physician, 
and through his kindness it becomes possible to throw as much light on 
human embryology as on that of any of the other mammals. During 
the last few years several embryologists, especially Prof. His, have not 
only added a great deal to our knowledge of human embryology, but 
3 Outlines of Entomology. Prepared for the use of farmers and horticulturists. By 
Mary E. Murtfeldt. Report of the Missouri State Horticultural Society for 1890. Also 
‘issued separately, pp. 130, Figs. 48. 
1 Edited by C. O. Whitman, Clark University. 


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