Geology and Natural History. 167 



sometimes different from that of those which inhabit the other. 

 In this species the adults also are different from each other, but 

 as we found a perfect series of transitional forms there is no good 

 reason for regarding them as specifically distinct; and in the case 

 of the other species — Alpheus heterochelis — we were unable, after 

 the most thorough and minute comparison, to find any difference 

 whatever between adults from North Oai'olina and those from the 

 Bahama Islands, although their life histories exhibit a most sur- 

 prising lack of agreement. In fact, the early stages in the life 

 of Alpheus heterochelis in the Bahama Islands differ much less 

 from those of Alpheus minor or Alpheus Normani than they do 

 from those of the North Carolina Alpheus heterochelis • and, ac- 

 cording to Packard, the Key West heterochelis presents still an- 

 other life history. 



In the summer of 1881 I received the American Naturalist with 

 Packard's very brief abstract of his observations at Key West 

 upon the development of Alpheus heterochelis, and read with 

 great surprise his statement that this species has no metamor- 

 phosis, since, while still inside the egg, it has all the essential 

 characteristics of the adult. As I had under my microscope at 

 Beaufort on the very day when I read his account a newly 

 hatched larva of the same species and was engaged in making- 

 drawings to illustrate the metamorphosis of which he denies the 

 existence, and as my experience in the study of other Crustacea 

 had taught me that all the larvae of a species at the same age are 

 apparently facsimiles of each other down to the smallest hair, 

 Packard's account seemed absolutely incredible, and I hastily 

 decided that, inasmuch as it was without illustrations and was 

 written from notes made many years before, it involved some 

 serious error and was unworthy of acceptance. This hasty 

 verdict I now believe to have been unjust, since my wider ac- 

 quaintance with the genus has brought to my notice other 

 instances of equally great diversity between the larvae of differ- 

 ent specimens of a single species. 



The phenomenon is, however,, a highly remarkable one and 

 worthy the most thorough examination, for it is a most surpris- 

 ing departure from one of the established laws of embryology — 

 the law that the embryonic and larval stages of animals best 

 exhibit their fundamental affinities and general resemblances, 

 while their specific characteristics and individual peculiarities 

 make their appearance later. 



This is one of the important subjects illustrated in the follow- 

 ing descriptions. 



12. Morphologische Studien von K. Schumann, lte Abtheilung. 

 — 206 pp., 6 Tal'eln. 8vo. Leipzig, 1892 (Wm. Engelmann.) — Prof. 

 Karl Schumann has just published the first part of his '' Morpholo- 

 gische Studien," in continuance of his investigations into the anat- 

 omy of the flower. These studies will concern themselves not only 

 with flower-structure but also with the anatomy of flowering plants 

 in general, along the lines laid down by Hofmeister in his " Allge- 

 meine Morphologic" The first half of this part, therefore, is 



Am. Jour. Sci. — Third Series, Vol. XLV, No. 266.— February, 1893. 

 12 



