84 



On making- a series of sections tliiough a branch in order 

 to compare the general anatomy of this species with that of 

 Gorgonia liammea, I was surprised to find numerous oval 

 bodies, the largest of which were i by 0.8 mm. in size, situated 

 in what appeared to be special sacs in the coenenchym. These 

 bodies proved to be embryos, and each one lies in a special 

 enlargement of one of the intermesenterial spaces of a polyp. 



In most cases there is only one embryo to each polyp but 

 not unfrequently there are two. There are very few barren 

 polyps, except at the ends of the branches, and as some of the 

 pregnant polyps are killed expanded and in all cases their 

 tissues are in a healthy state, there is no reason to suppose 

 that the digestive function is interfered with by the embryo. 

 There is certainly no evidence of dimorphism such as occurs 

 in Paragorgia, in which the siphonozoids produce the gonads 

 and the autozooids are sterile. 



It is interesting to speculate on the mode of discharge of 

 these embryos. As the mouth of the polyp can not be more 

 than 0.0 1 mm. in length, i.c,, one-hundreth part of the length 

 of the embryo, it is improbable that they are discharged 

 by the mouth after the manner of the ova of other Alcyonaria. 

 I have observed that in the older branches of the specimen 

 the crust of coenenchym covering the axis has a longitudinal 

 split of considerable length, and that below this the coenen- 

 chym is thin and without embryos. It seems to me, then, to 

 be possible that the coenenchym is actually ruptured from 

 time to time to allow the escape of the embryos, and is after- 

 wards regenerated. 



The princpal interest of the specimen, however, is that it 

 affords a rare instance of viviparity among the Alcyonarians. 

 There is a figure in Kollikers Icones XIV 3 of Gorgonia 

 (Pterogorgia) pinnata, in which the polyp cavity is shown in 

 section to be divided by a septum into two compartments, 

 and this figure reminds me very forcibly of some of the 

 sections in my series which were cut through the brood cham- 

 ber without actualy touching the embryo. There is no 

 mention in the text, however, of any embryos, and it is pos- 

 sible that this second chamber in Kolliker's figure has some 

 other meaning *. 



♦Lacaze Duthiers (i) proved the precious coral to be viviparous, and according 

 to Marion ai d Kowalewsky the " Clavulaires petricoles" are viviparous, but the 

 ** Clavulaires des Posidonies " are oviparous. Sympodium (Alcyonium) coralloides 

 is also according to these authors viviparous. Koren and Daniellsen (8) state that 

 three species of Nepthya found at depths of 269-761 fathoms are viviparous. These 

 are, I believe, the only authenticated cases of viviparity among Alcyonarians 

 hitherto recorded. Gorgonia capensis affords the first instance of viviparity that I 

 have come across in my studies of Alcyonarians. 



