LITERARY NOTICES. 



419 



large number of students of astronomy whose 

 instrumental equipment is not adequate to 

 the satisfactory observation of a consider- 

 able proportion of the objects described in 

 Smyth's and Webb's catalogues of celestial 

 objects suited to observations with common 

 telescopes. Those who have equatorially 

 mounted telescopes of more than three or 

 four inches aperture may find these works 

 all they need; but those who have only alt- 

 azimuths of smaller apertures will be liable 

 to embarrassment from the difficulty of lo- 

 cating the objects described in these works, 

 and by the presence in their lists of many 

 that can not be seen at all with those instru- 

 ments. For the purposes of this work ob- 

 jects are selected which are within the powers 

 of such instruments, and the attempt has 

 been made to describe their location so that 

 they may be easily found without the aid of 

 a map or lantern light. Price, $1.25. 



Hermon C. Bampus has had in mind, in 

 the preparation of his Laboratory Course in 

 Invertebrate Zoology (Henry Holt & Co., New 

 York, $1), the requirements of a class of 

 students who are pursuing a course of labo- 

 ratory work on the subject. An effort has 

 been made to direct the work without actu- 

 ally telling the student all that is to be 

 learned from the specimen. An instructor 

 is supposed to be present to assist with the 

 hard points, and to demonstrate what can 

 not well be elucidated by written descrip- 

 tions. Not always the most typical animals 

 are selected, but forms easily procured and 

 preserved have been looked for. The orders 

 of Protozoa, Coelenterata, Echinodermata, 

 Vermes, Mollusca, Crustacea, Limulus, Arach- 

 noidea, and Antennata are represented by 

 from two to seven genera each. 



The work of Dr. Hermann Adicr on Al- 

 ternating Gcneralions, based on A Biological 

 Study of Oak Galls and Gall Flies, is pub- 

 lished by Macmillan & Co., translated with 

 the permission of the author, and edited by 

 Charles R. Stratton. The translator became 

 acquainted with the work while studying 

 galls as a branch of comparative pathology, 

 and was struck with its originality and the 

 light it threw upon certain great biological 

 problems. Dr. Adler began his observations 

 of gall flies in 1875, and in the course of his 

 investigation was able to unfold their life 

 history, and to prove that, while many spe- 



cies are linked together in alternate agamous 

 and sexual generations, others are wholly 

 agamous. Since the existence of alternat- 

 ing generations was discovered by Chamisso, 

 fresh instances of like phenomena have ac- 

 cumulated in which the life-cycle of the spe- 

 cies may be represented by two or more 

 generations, differing in form and organiza- 

 tion, existing under different conditions, and 

 reproducing themselves in different ways. 

 While the galls and their generations are 

 described by Dr. Adler, the translator sug- 

 gests in the introduction a number of inquir- 

 ies respecting the philosophy of the phenom- 

 enon, and especially concerning the nature 

 and operation of the excitation by which the 

 peculiar fruitlike forms are produced upon 

 the trees as the result of the gall fly's work. 

 Colored illustrations are given of foi-ty-two 

 species of oak galls. Price, $3.25. 



Canadian Independence, Annexation, and 

 British Imperial Federation (Putnams, 75 

 cents) is the amplification of an essay first 

 written for Canadian readers by a Canadian, 

 James Douglas, long resident in the United 

 States. The imminence of political change 

 in Canada, independence as an essential fac- 

 tor of imperial federation, annexation as an 

 alternative to independence, Canada's slow 

 progress, the probable effect of annexation 

 on Canadian industries and wages, annexa- 

 tion from the point of view of comparative 

 politics, and annexation from American and 

 Canadian points of view are considered. The 

 author believes that all the advantages ex- 

 pected from annexation can be obtained by 

 reasonable trade arrangements. 



An elementary text-book, with the title 

 Geometry for Grammar Schools, has been 

 prepared by E. Hunt, LL. D. (Heath). Large 

 use of drawing is made in it, and paper cut- 

 ting and folding are somewhat employed. 

 The problems are an extension of those on 

 mensuration usually found in text-books of 

 arithmetic. Two copies of a protractor are 

 printed in such a manner that the pupils 

 may cut them out and use them in drawing. 



Prof. Dolbear^s book, Matter, Ether, and 

 Motion, the first edition of which was noticed 

 in this magazine in 1892, has reached a sec- 

 ond edition (Lee & Shepard, $2). Three 

 chapters have been added, dealing respec- 

 tively with Properties of Matter as Modes of 

 Motion, Implications of Physical Phenomena, 



