OUTLINES OP COMPARATIVE EMBRYOLOGY; 



OR, Life Historibs of Animals, including Man. By A. S. Pack- 

 ard, Jr. Copiously Illustrated. 8vo. |3.50. 



"An ample work o( reference for advanced students It would not be 



easy to find a work on the branch of Animal Physiology of which it treats which dis- 

 plays so acute and delicate analysis, or presents a more complete statement of the 

 recondite facts."— rriSane. 



" Must remain for many years the one standard work on the subject. . . . Alto- 

 gether it forms one of the most valuable works of science yet published in this coun- 

 ri-y, and it is safe to say that no working naturalist can do without it." — Prof. E. S. 

 iloRsE, in Popular Science Monthly, 



"It occupies worthily an important place absolutely unfilled to this time."— Chan- 

 cellor WiNCHELL. 



GUIDE TO THE STUDY OF INSECTS, 



AND A Treatise on those Injurious and Beneficial to Crops. 

 For the use of Colleges, Farm- Schools, and AgricuUunsis. By 

 A. S. Packard, Jr., M.D. Witli 11 Plates and 650 Woodcuts. 

 Sixth edition. $5. 



" I hold that your work ought, in connection with Harris's 'Treatise on Inspects 

 Injurious to Vegetation,' to which it is, as it were, the key, to he introduced in all our 

 agricultural colleges, as the best test-book of that kind, now extant, "—Prof essor L. 

 Agassiz. 



"Your 'Guide to the Study of Insects' has become the text-book up here."'— 

 G. Crotch, Librarian of Cambridge University, England. 



"But it is of its scientific merits especially we wish to speak, and of which we can 

 speak in no qualified terms of praise. The first two parts are, we do not hesitate to 



afiirm, the best things of the kind that our language possesses We have 



seldom fallen on so thoroughly good a scientihc treatise, and we can only conclude 

 our notice of it by advising all our natural history readers to make its acquaintance. 

 There is no work ^ve should prefer to it as a book for the student." — Scientific Opin- 

 ion, London. 



"Among the best guides to the study of insects which at present exist in our liter- 

 iiture."— Dr. A. Dohkn, in the Entomological Journal, of Stettin. Prussia. 



"The study of Entomology is one that can be almost as easily pursued in the 

 school-room as* Botany, and we should be glad to see the experiment tried. Dr. 

 Packard's work is well fitted, by its clear, simple style, for use as a text-book."— y/ie 

 Michigan Teacher. 



"In typography and illustrations, the part before us leaves nothing to be desired, 

 while the author's style is very perspicuous. We hope the work will be used as 



intended, in colleges and farm-schools and by agriculturists In every 



particular of text, illustrations, and manufacture, it is thoroughly well done."— 7"/'^ 

 Nation. 



"Altogether, we are immensely pleased with this work. It is assuredly, all in all, 

 the fullest' most modern, and most clearly-written treatise on insects we have e\ er 

 ^ten.''— Popular Science Beview, London. 



" The most recent memoirs connected with these subjects have been made use of 

 bv the author ; and this part of his work is certainly the best manual of entomology 

 which the English reader can at present ohtidn.''— Nature, London. 



"As a practical treatise on American entomology, with reference especially to the 

 insects injurious or beneficial to crops, it stands almost alone, and reflects the highest 

 credit upon American scholarship, patience, and scientific skill."— j\''^«' 3 ork Tribune. 



HENRY HOLT & CO., Publishers, NEW YORK. 



