56 The American Naturalist. (January, 
of this form with the vomerine teeth, discovered by Baur, and refers to 
their relationship to similar teeth in Paleohatteria. 
Dr. Emil Schoebel contributes” an account of the post-embryonic 
development of the eye of the Amphibia. The eye has almost all of 
its essential features at the beginning of larval life, and, contrary to 
the title of the paper, the author describes the features before as well 
as after hatching. 
`. EMBRYOLOGY .! 
A New Text-Book on the Embryology of Invertebrates. 
—Dr. E. Korshelt and Dr. K. Heider have recently published the first 
volume of a ‘‘ Lehrbuch der Vergleichenden Entwicklungsgeschichte 
der Wirbellosen-Thiere’’ (Jena, 1890, Gustav Fishcher). Since the 
publication of Balfour’s ‘‘ Treatise on Comparative Embryology,” 
written more than ten years ago, there have been published an in 
mense number of papers dealing with the embryology of animals; and 
the authors believe there is a pressing need of bringing these together, 
and making a new inventory of the accumulated material. The pres- 
ent book is confined to the results on invertebrates, inasmuch as the 
papers on vertebrate embryology have been brought together, within 
the last few years, in well-known treatises on the subject. The first 
volume treats of the Sponges, Cnidaria, Ctenophora, Platyhelminthes, 
Nemertines, Nemathelminthes, Annelids, Echinoderms, and a iew 
smaller groups. In the second volume the authors promise to treat of 
the Arthropods, Molluscs, Molluscoids, Tunicates, and Amphioxus; 
and the book will close with a general part. 
The substance of the first volume is largely made up of reviews of 
the most important papers published since Balfour’s time, and, so far as 
we can judge, these are admirably presented, and are noticeable for 
clearness as well as conciseness of statement. The authors believe — 
fully in the evidence of embryology to solve most of the problems of 
Phylogeny. They hold fast to the gastrula ancestry of the Metaz0@ — 
and each larval form is marshaled up to tell its tale of how the groupè — 
arose. This diagrammatic conception certainly admits of clearness ©” [ 
treatment ; but whether it represents the high-water mark of morpho- 2 
logical speculation may be open to doubt. 
12 Zool. Jahrbuch, Abth. Anat. Ont., IV., p. 297, 1890. 
1 Edited by Dr. T. H. Morgan, Johns Hopkins University, Baltimore, Md, to whom n 
boo! ks review sh e sent. . 
