Ivi 



from the idea that they formed the genetic connection between 

 the great groups which they serve to connect.* 



A memoir on the " Ontogenie " and " Philogenie " of insects, 

 by Dr. Paul Meyer, is published in the tenth volume, or vol. 3 of 

 the new series, of the ' Zeitschrift fiir Naturwissenschaft' of 

 Jena, 2nd Heft. 



A very valuable contribution to the knowledge of the earliest 

 stages of many of the higher Crustacea is to be found in * TJnter- 

 suchungen zur Erforschung der Genealogischen Grundlage des 

 Crustaceen Systems— Ein Beitrag zur Descendenzlehre,' pp. 124, 

 folio, Wien, 1870, with nineteen plates and twenty-five woodcuts, 

 by Carl Claus. In this work the author gives the most careful 

 descriptions and figures of the larvse or zoea states of numerous 

 species of Pal^emonidge, Squillidse, Nebalia, Sergestes, Palinurus, 

 Scjdlarus, Pagurus, Porcellana, Maia, Inachus, &c., with addi- 

 tional descriptions and details of the Copepoda, Cirripedia, 



* In the course of his introductory lecture to the Natural History Class in the 

 University of Edinburgh at the commencement of last November Term, Professor 

 Sir W^yville Thomson made reference to the evolution hypothesis. He said that the 

 great stumbling block, from the natural history side of the question, in the way of 

 our at once accepting the evolution hypothesis, was that any such passage from one 

 species to anything but that, was entirely outside our experience. The horse 

 evidently had been the horse since the earliest hieroglyphs were engraved on 

 Assyrian monuments and tombs; and the same held for all living creatures. 

 There was not a shadow of evidence of one species having past into another during 

 the period of human record or tradition. Nor was this all : we had, in the fossil 

 remains contained in the rocks, a sculptured record of the inhabitants of this world, 

 running back incalculably further than the earliest chisel mark inscribed by man — 

 incalculably further than man's existence on this planet; and although we found 

 from that record that thousands of species had passed away, and thousands had 

 appeared, in no single case had we yet found the series of transitional forms imper- 

 ceptibly gliding into one another and uniting two clearly distinct species by a 

 continuous bridge, which could be cited as an undoubted instance of the origin of a 

 species. Profound mystery still involved the birth of the new specific forms. Mr. 

 Darwin's magnificent theoi-y of " natural selection " and the " survival of the fittest," 

 had undoubtedly shaken the veil by pointing out a path by which it was conceivable 

 that such an end might be attained ; but it had by no means raised it, for every new 

 instance which he produced and developed with such eloquence and skill, of the 

 marvellous changes which animals underwent under varying conditions, somehow 

 always appeared to emphasize the fact that, however far variations might be carried, 

 the limit of specific identity was in our experience never overpassed. Still, even if 

 we never found out the precise mode in which one species gave rise to another, there 

 could, he believed, be no further hesitation in accepting generally a hypothesis of 

 evolution, and in regarding our present living races as the ultimate twigs of a great 

 genealogical tree whose gradually coalescing branches we could trace downward, if 

 our infonnation were complete, to the dawn of geological time. 



