64 



'i. On the Gravid Period in Lagenorhjnclins albirostris, Gray. 



In his interesting and valuable work, "'Histoire Naturelle des Delpliinides" (p. 137), P. J. van Beneden says: 

 „Nous ne connaissons presque rien de precis au sujet de I'epoque de leur parturition, et des lieux ou elle s'eiifectue. Une 

 femelle, dont le docteur Joases fait mention, était grosse au mois de Mai. En Juillet 1862, deux femelles pleines, capturées 

 sur les cotes de Suéde .... portaient chacune une jeune de 3 pieds de longueur ... En Septembre, 1881, on a capture 

 im jeune animal qui avait encore une parti de son cordon ombilical. D'apres cela, il faut croire que la parturition a lieu 

 au milieu de Tété, sans doute en Juin et Juillet, dit le professeur Sir W. Turner." 



We are tempted still to abide by this statement, as the material before us does not allow of any more decisive 

 conclusions. 



Of the fcetuses here desci-ibed, one 765 millim. in length was taken in the middle of April, one 720 millim., and 

 one 1130 millim. in length, in about the middle of May. These measurements are not materially at variance with Sir 

 William Turner's oi^inion, with which van Beneden also coincides, namely, that it brings forth in the middle of summer. 

 As previously stated in the section on this species (p. 27), I take the size of the newly-born animal to be Vt that of the mother. 



As the measurements are far from numerous, no more direct conclusions can at present be drawn. 



3. On Gravidity in Orca gladiator, Lacépéde. 



Acquaintance with facts concerning this cosmopolitan Cetacean's copulation and gestation is also very slight. P. 

 J. van Beneden, in his interesting "Histoire naturelle des Delpliinides", etc. 1889, says: "Nous ne connaissons rien des 

 amours de ces Cétacés (i. e. Orca gladiator), ni des lieux ou ils mettentbas; nous savons seuleraent qu"ils vivent en polygamic 

 comme les Cachelots, et nous n'avons que quelques exemples de femelles pleines captui'ees, mais en trop petit nombre pour 

 apprécier a quel epoque de I'annee ils mettent bas, et pour connaitre les lieux ou cette operation s'accomplit. Dans la 

 gamme de dix-huit individus qui s'est perdu au mois de Février, 1871, sur les cotes de Shetland, se trouvaient deux femelles 

 pleines, dont un ftetus mesurait environ deux pieds. La mere, ayant au moins dix-huit pieds, il y a lieu de croire que 

 Taccouplement, ou du moins la fécondation, a eu lieu la fin de I'ete.'" 



This supposition of Van Beneden is very correct on the whole, and more light is thrown upon these circumstances 

 by observations taken on the coast about Bergen. 



The stranding of Orca gladiator is not an uncommon occurrence on the coasts of Norway, and for the last ten 

 years, fætuses from such specimens have been collected and preserved. James Grieg (Cetological notes in the Bergen Museum's 

 Report for 1889) furnishes the following data: 



In the beginning of 

 February 1885, 62 specimens were taken on Bildøen in the neighbourhood of Bergen, among which were 6 young ones 



and 12 gravid females, whose small ffctuses measured from 408 millim. (the smallest) to 875 millim. in length. 

 On the 18th Feb. 1886, 3 fætuses were sent to the Bergen Museum from Herlø near Bergen, one 590 millim. one 820 



millim. and one 860 millim. in length. 

 November, 188 7, in the middle of the month, 13 specimens of Orca were taken on Bildøen near Bergen, 2 of which were 



gravid females. Their fætuses were 1870 millim. and 2080 millim. in length. 

 On the 2 6th Jan. 1891, a yoimg female, 2.51 metres in length was taken. It was stuffed and placed in the University's 



Zoological Museum (Christiania), its skeleton being placed in the zootomical collection of the university. 

 On the 29th April, 1892, Bergen, according to information obtained from Dr. Danielssen, acquired a female foetus 690 



millim. in length. 



When we put together these facts about fætuses, from that 2 feet (about 62 centimetres) in length, from the 

 Shetland Isles, to those mentioned here, their length appears to vary between 40 and 87 centimetres in the month 

 of February. In April, we have only one observation, a specimen 69 centim. in length (1892). In November, Grieg 

 has measured two fætuses, one 1.87 metres, the other 2.08 metres in length. The latter may certainly be considered to be 

 fully developed. Young ones accompanying the mother animal have frequently been observed: the 2.760 metres 

 long skeleton of the young one taken on the 27th Sept. in Limfjord, Denmark, and described by Liitken (see literature 82) 

 is well known in cetological literature. A female, 5.25 metres in length, and accompanied by her young one, was taken, in 

 1878, in Trondhjem's Fjord (cf. R. Collett, Nyt Mag. f. Naturvidensk. 22 Bd. p. 250). According to our observations 

 here mentioned, a young one 2V2 metres in length was caught at the end of January, 1891, and 6 young ones were observed 

 in the take on Bildøen (Bergen) in February, 1885. 



