Crustacea, 44, 126, 1867; 48, 244, 430, 1869; 25, 119, 534, 1908.
Ascidians, 1, 54, 93, 211, 288, 443, 1871; 20, 251, 1880.
Dredging operations and marine fauna, 49, 129, 1870; 2, 357, 1871; 5, 1, 98, 1873; 6, 435, 1873; 7, 38, 131, 405, 409, 498, 608, 1874; 9, 411, 1875; 10, 36, 196, 1875; 16, 207, 371, 1878; 17, 239, 258, 309, 472, 1879; 18, 52, 468, 1879; 19, 137, 187; 20, 390, 1880; 22, 292, 1881; 23, 135, 216, 309, 406, 1882; 24, 360, 477, 1882; 28, 213, 378, 1884; 29, 149, 1885.
Miscellaneous, 39, 221, 1865; 41, 249, 268, 1866; 44, 126, 1867; 48, 92, 1869; 3, 386, 1872; 7, 134, 1847; 10, 364, 1875; 16, 323, 1878; 20, 251, 1880; 3, 132, 135, 1897; 9, 313, 1900; 12, 88, 1901; 13, 327, 1902; 14, 72, 1902; 15, 332, 1903; 24, 179, 1907; 29, 561, 1910.
S. I. Smith describes the metamorphosis of the Crustacea (3, 401, 1872; 6, 67, 1873), species of crustacea (3, 373, 1872; 7, 601, 1874; 9, 476, 1875), and dredging operations in Lake Superior (2, 373, 448, 1871). In this series occurs also a series of papers on comparative anatomy and embryology from the Chesapeake Zoological Laboratory in charge of W. K. Brooks. In the 39th and 40th volumes of the third series (1890) occur several papers on evolutionary topics by John T. Gulick (39, 21; 40, 1, 437) which have attracted much attention.
Before the end of this period, however, the Journal was relieved from the necessity of publishing zoological articles by the establishment of several periodicals devoted especially to the various fields of zoology. We find, therefore, but few exclusively zoological papers after 1885, although articles of a general biological interest and the reviews of zoological books continue.
In the fourth series of the Journal, beginning in 1896, occur also a number of articles on systematic zoology by Verrill and others and several papers having a general biological interest. Brief reviews of a small number of zoological books are still continued, but at the present day the Journal, which played so important a part in the early development of American zoology, has been given over to the geological and physical sciences in harmony with the modern demand for specialization.
Period of Experimental Biology, since 1890.
Zoological studies remained in large measure observational and comparative until about 1890 when the experimental methods of Roux, Driesch and others came into prominence. Interest then turned from the accumulation of facts to an analysis of the underlying principles of biological phenomena. The question now was not so much what the organism does as how it does what is observed, and this question could be answered only by the experimental control of the conditions. These experimental studies met with such remarkable success that in a few years the older morphological studies were largely abandoned, the Morphological Society changed its name to the Society of Zoologists, and in 1904 the Journal of Experimental Zoology was established. The experimental methods were applied to all branches of biological science, and while it must be freely admitted that little progress has been made toward an understanding of the ultimate causes which underlie biological phenomena, a great advance has been made in the elucidation of the general principles involved.
Experimental embryology, histology, regeneration, comparative physiology, neurology, cytology, and heredity have in recent years successfully adopted an experimental aspect and have made significant progress thereby. Biology has now taken its place beside chemistry and physics as an experimental science.