Cetacea and the whales proper, tlieir habits and anatomy, as far as they were then known, being shortly treated of. 

 Concerning their breeding he says (p. 177): "Les femelles des dauphins resolvent dans raccouplement les måles en les 

 serrant entre leurs nageoires. On dit que la gestation est de dix mois, et que la conception a lieu dans I'automne; on assure 

 aussi qu'elles ne font qii'nn petit on deux h chaque povtée, et que la mere surveille avec sollicitude leurs mouvements, les 

 fagonne ou les habitue å la natation . . . . Ce n'est qu'en se penchant sin- le cote que les jeunes dauphins saisissent le 

 iianielon du sein de leur nourrice, et qu'ils y puisent un lait onctueux, de couleurs bleuatres, mais trés-nourrissant." 



In the well-known '"Jledicinische Zoologie" by Brandt and Ratzeburg, where Physeter, Balæna and several 

 other Cetacean genera are described with special reference to their outward form and skeleton, and to the products they 

 yield which are used in medicine, nothing new is found about the gravidity or the embryo of these animals. 



Georges Cuvier has also rendered great services to Cetology, notwithstanding the mistakes he has made cm 

 certain points, e. g. the geographical distribution of the Greenland whale. A\'ith his critical ability and thoroughness he 

 brings order into the numerous descriptions and the confusion of names, searching for literary sources, and procuring osteological 

 signs for the identiticatinn of the species. His works are therefore of considerable value with regard both to the systematisui 

 and anatomy of these animals; but it did not fall to his lot to contribute any fresh facts about their breeding and developement. 



Nor does F. Cuvier, in his well-known "Histoire Naturelle des Cétacés," seem able to extend the knowledge in 

 these particulars, for he says (p. XXIV seq.): "On ignore d'accouplernent des Cétacés souftieurs. Personne jusqu'a present 

 n'en a été témoin. L'opinion la plus probable, c'est (lu'ils s'unissent couches tous deux sur le cote .... On ignore aussi 

 la durée de la gestation que quelques-uns portent a dix mois pour la baleine, dont le jeune, en naissant, aurait vingt pieds 

 de longueur." He then enters into the subject of suckling. After describing the different Cetacean forms, — certain of the 

 descriptions being undoubtedly based partly on autopsy, — he gives in conclusion a good, though scarcely complete list f)f 

 the literature on this subject. 



In the first half of the present century, we find a numlier of cetological treatises, some of them descriptions of 

 stranded specimens, others, anatomical pamphlets. Inquiry seems to be trying to make up for the previous neglect of these 

 giant organisms of the world. A\'hile there have appeared as we have seen, large collections of accounts of the true and 

 the herbivorous Cetacea in French zoological literature, we find on the English side a number of special descriptions following 

 John Hunter. Contributions to Cetology have also been made by German naturalists, the Phocæna communis having been 

 taken as the model, and in the main furnishing material for special descrijjtions. 



We find an eminent explorer in the field of Cetology in Rapp, who in his well-known little book. "Die Cetaceen 

 zoologisch-anatomisch dargestellt" 1837, has recorded the outlines of the anatomy of these animals, based upon careful 

 observation and thorough study, while besides the addition of fresh information, he critically sifts the already existing material. 

 He had not. however, an opportunity of becoming acquainted with Cetacean embryonic forms. He states that he found in 

 the uml)ilical cord of a Phocæna 2 arteries and 2 veins, and that the urachus seems to be open until the birth of the 

 young one. "Ueber die Fotushiillen der Cetaceen fehlt es an Beobachtungen," he says, quoting from E. Home the statement 

 that the chorion takes the place of the placenta, as in the sow and the mare. 



Nor has Karl Ernst von Baer, in his famous work "Ueber Entwicklungsgeschichte der Thiere," much to say 

 about the developement of the Cetacean type, for he states that he knows nothing about the ovum of the Cetacea. liut that 

 he believes, from the remarks made about it in literature, that no placenta is formed, and that the ovum shows conditions 

 similar to those in the Pachydermata. He has only had the oppoi-tunity of seeing one embryo 9 inches in length, — a 

 narwhal, whose navel string had only a single umbilical vein, a fact which he emphasized in contradiction to Rudolph's observation 

 of 2 umbilical veins in Phocæna. 



Towards the middle of the present century a new era in cetological investigation liegins with the production by 

 the well-known Danish naturalist D. F. Eschricht of a series of works on Whales, based on studies of embryonic forms. 

 Part of his material was obtained from Bergen in Norway — where for centuries captures of Balænoptera rostrata and 

 some species of Dolphin have been made, — and part from the now-existing Danish colonies in Greenland. We thus find 

 in Eschricht for the first time, a more detailed description of some large and small embryos. In additi(m to Balienoptera 

 rostrata, the embryonic forms of Megaptera boops and Hyperoodon diodon and their anatomy are described. In an 

 earlier work, from 1837. he has described the fietal membranes in a gravid Phocæna. In Eschricht and Reinhardt's 

 well-known monograph on Balæna mysticetus, L., the subject of the duration of its gestation is also touched upon. 

 Eschricht directs the attention of investigators to embryonic forms as a means of learning to know many of the conditions 

 in the full-<Trown anmial. This is due to the circumstance that the ^^'hale cinbi'vo verv early assumes the generic and specific 



o 



characters, — a fact which is clearly shown in the present treatise. 



Although embryonic forms are only occasionally mentioned by more modern authors. — their size and dimensions 

 i)cing generally given in conjunction with descriptions of full-grown animals, — we have contributions to the knowledge ot 

 the fu'tr.l membranes in the Cetacea. from Owen. ('. D. Meigs and KoUeston. It is to the eminent naturalist Sir William 



