148 Mr MacBride, On the Development [Feb. 9, 



tributed in the coenosarcal canals of the growing edges of the 

 colony. 



In Millepora murrayi from Torres Straits large well-marked 

 medusae, bearing the spermaria, were observed lying in ampullae 

 of the ccenosteum. Even when free from the coenosarcal canals 

 and ready to escape they show no tentacles, sensory bodies, radial 

 or circular canals, velum or mouth. They are formed by a simple 

 metamorphosis of a zooid of the colony. The eggs of this species, 

 like those of M. plicata, are extremely small and amoeboid in 

 shape. They are not borne by special gonophores. 



In the Stylasteridce, the eggs are large, contain a large quantity 

 of yolk, and are borne by definite cup-like structures produced by 

 foldings of the coenosarcal canals. 



In Allopora the spermarium is enclosed by a simple two 

 layered sac composed of ectoderm and endoderm. The endoderm 

 at the base is produced into the centre of the spermarium as 

 a simple spadix. 



In Distichopora the male gonophores are similar to those of 

 Allopora, but there is no centrally placed endodermal spadix. In 

 both genera a two layered tube (seminal duct) is produced at the 

 periphery of the gonophore when the spermatoza are ripe. 



Neither the gonophores of Allopora and Distichopora, nor the 

 medusae of Millepora murrayi show any traces in development of 

 being degenerate structures like the adelocodonic gonophores of 

 the other Hydromedusce. 



(4) The Development of the Oviduct in the Frog. By E. W. 

 MacBride, St John's College. 



[Abstract: received February 9, 1891.] 



In July of last year I undertook, at Mr Sedgwick's suggestion, 

 the investigation of the origin and growth of the oviduct in the 

 Frog. Some considerable time was spent in determining the 

 stages in which it is formed. No trace of it is visible till the 

 animal has lost all the characteristic tadpole organs except the 

 tail; and it is complete, from a morphological point of view, 

 when the frog has attained a length of about 17 millimetres, after 

 the tail has been absorbed. 



So far as I am aware, there are only two papers dealing with 

 the development of this duct in the Anura. The first of these is 

 by C. K. Hoffmann, in the 'Zeitschrift fur wissenschaftliche Zoo- 

 logie ' for 1886 (Bd. 44), and the other' by A. M. Marshall and 

 E. J. Bles, in the second volume of the ' Studies from the Biolo- 

 gical Laboratories of the Owens College.' 



Hoffmann describes the duct as arising from a patch of modified 

 peritoneum just ventral to the third and now only remaining 



