BOTANY. 



teachers. This is Huxley and Martin's "Ele- 

 mentary Biology." One result of the publica- 

 tion of Sachs in English has been to multiply 

 elementary text-books modeled after it, to suit 

 the needs of beginners. The first to appear 

 was " A Text-Book of Structural and Physio- 

 logical Botany," by O. W. Thome, translated 

 and edited by Prof. Bennett in 1877. In 1880 

 appeared a " Botany for High Schools and Col- 

 leges," by 0. E. Bessey ; and in the same year 

 an "Elementary Text-Book of Botany," by 

 K. Prantl, translated by S. H. Vines. A still 

 more elementary work on the same plan is 

 " The Essentials of Botany," by 0. E. Bessey 

 (1884). 



In plant physiology proper, which involves 

 special and costly apparatus, for the purpose 

 of original work, and also special training on 

 the part of the experimenter, very little has 

 been done in America, and there are only one 

 or two universities where there is sufficiently 

 good apparatus for repeating the more complex 

 of the modern experiments. 



Professorships. There are professorships of 

 botany alone at Harvard, Brown, Yale, Am- 

 herst, Cornell, the University of Pennsylva- 

 nia, Ohio State University, the University of 

 Michigan, Michigan Agricultural College, the 

 University of Wisconsin, Iowa Agricultural 

 College, the University of Nebraska, and at a 

 few smaller institutions. Four fifths of these 

 have been created within fifteen years, and 

 more than half in the past ten years. In some 

 of the Western institutions horticulture is added 

 to the botanical chairs ; but botany is taught 

 much more generally and efficiently than ten 

 years since in many schools and colleges where 

 it is included in the chair of Natural History, 

 and where there is often excellent botanical 

 instruction. In all the above-mentioned col- 

 leges, advanced courses are laid out, and in 

 most an opportunity is given for biological 

 study with the microscope and other appli- 

 ances in the laboratory. It may be said, in 

 passing, that the prices of microscopes have 

 been greatly reduced within the past ten years, 

 They are now nearly as cheap, and the stands 

 as convenient, as European instruments. 



Formerly, the general opinion prevailed in 

 this country that "analysis" of species was 

 the sum and substance of all laboratory work. 

 At present, in all the better laboratories, this 

 is made subordinate to other and better meth- 

 ods. The careful study of typical forms of the 

 flowering plants, and field-work, including the 

 collecting and preservation of specimens, are 

 generally encouraged, however. The princi- 

 pal canons, in the present code of biological 

 laboratory instruction, may be put in words as 

 follow : 1. Carefully observe and study typical 

 forms. 2. Assist the observation by drawing 

 and describing the objects studied. 3. Com- 

 pare different forms studied with one another. 



Publications : Plant Anatomy and Physiology. 

 In considering the published work especial- 

 ly of the past ten or fifteen years that in 



the field of plant anatomy and physiology is 

 the most remarkable in respect to the addi- 

 tions made to our knowledge. De Bary's 

 treatise on the " Comparative Anatomy of the 

 Vegetative Organs of Phanerogams and Ferns," 

 issued in German in 1877, and in English in 

 1884, is by far the fullest and ablest treatise of 

 recent years. It is a discussion and classifi- 

 cation of the so-called elementary tissues, and 

 the tissue systems formed by them. The author 

 gives a considerable number of illustrations of 

 the different types of structure of the meristem 

 of roots and stems, a subject not fully devel- 

 oped till recently. It will serve as a complete 

 hand-book in vegetable anatomy for some 

 years to come. Since 1880 considerable has 

 been written, mostly in German, on the struct- 

 ure of the protoplasm in a growing cell, and 

 the kindred question of the formation of the 

 cell- wall, its structure, and its increase in sur- 

 face and thickness; indeed, it involved the 

 whole question of the theoretic structure of 

 organized particles in plants, such as proto- 

 plasm, starch-grains, chlorophyll-bodies, and 

 the cell- wall. The recent work on the cell-wall 

 and protoplasm was begun by Schmitz in 1880 ; 

 on the structure and growth of starch-grains, 

 by A. F. W. Schimper in 1831, and in 1882 

 Strasburger published an important paper on 

 the "Structure and Growth of the Cell- Wall," 

 adopting and supporting the views of the two 

 botanists just mentioned, that the structure 

 and growth of all parts of living cells were 

 best explained by supposing chemically united 

 atoms to form minute particles, or "micellae," 

 which become aggregated by so-called " apposi- 

 tion " to form the various organized structures, 

 such as the cell-wall and various contents. 

 Any increase in thickness of a cell-wall was 

 asserted to take place by the addition of these 

 micellae in thin layers, one layer inside another. 

 Starch-grains, which usually show that they 

 are made up of concentric shells, are believed 

 to increase in a similar manner; that is, by 

 apposition of layers of particles over the layers 

 already formed. This theory is directly op- 

 posite to the one elaborated by Niigeli to ac- 

 count for the structure of similar bodies ; for 

 he supposes starch-grains to increase by the 

 intercalation of new molecules between the 

 old ones, which are theoretically held apart by 

 water surrounding them ; also that the outer 

 layer of the starch-grain is the oldest part, and 

 the center of the grain the youngest; the 

 formation of new layers taking place from 

 without inward, on the theory of the inter- 

 calation of particles. This theory is the one 

 advanced by Sachs in his " Text-Book." The 

 subject needs further elucidation, but the 

 weight of evidence seems to be in .favor of 

 Strasburger and Schimper. 



Another investigation, chiefly of recent date, 

 is upon the continuity of protoplasm through 

 the walls of cells in living tissue, by means of 

 minute openings or pits in the walls. The first 

 of the recent work on this was done about 



