twwiews = @aovvv 
THE DEVELOPMENT OF ASTERINA GIBBOSA. 309 
The Development of Asterina gibbosa.! 
By 
E. W. MacBride, 
Fellow of St. John’s College ; Demonstrator in Animal Morphology in the 
University of Cambridge. 
With Plates 18S—29. 
THE investigations which form the subject of the present 
memoir were commenced with the object of seeking in Asterids 
the results which the author (14) had already obtained from the 
study of Ophiurids, viz. the development of the so-called heart 
and its accompanying sinuses. 
A study of the literature soon led to the conclusion that our 
knowledge of the development of most organs in the Asterid body 
was very defective, and that a thorough revision of the whole 
embryonic and larval history would be most desirable. This 
work has occupied my attention for the last two years, and I 
am now in a position to give a fairly complete account of the 
whole organogeny; an account which will, I hope, place our 
knowledge of Asterid development on the same level as that 
to which our acquaintance with Crinoid ontogeny has been 
raised by the researches of Bury (1) and Seeliger (18) ; I have 
to express my warm thanks to Mr. Sedgwick not only for the 
suggestion of Asterina gibbosa as a proper type to investi- 
gate, but also for much assistance and advice in revising the 
proofs of this paper. 
That there was an immense lacuna in our knowledge to be 
1 A preliminary account of the observations recorded in this paper was the 
subject of the successful essay in the competition for the Walsingham Medal 
of the University of Cambridge in 1893. 
VOL. 38, PART 3.—NEW SER. Z 
