Minutes of Proceedings. 53 



highest invertebrate type, that of the Mollusca ; assimilating them- 

 selves most closely to the forms of the componncl Tunicated Ascidians, 

 in some of which many of the most eminent naturalists of the present 

 day are disposed to trace the primordial rudimentary source of the 

 vertebrata, the very highest type of animal organization. 



This important discovery was announced in the remarkable Paper 

 read by Dr. Allman to this Academy in 1852, and published in 

 volume xxii. of our Transactions. Since that time he has continued, 

 by Papers in the Scientific Journals, by Reports to the British Asso- 

 ciation, and by the admirable monographs published by the Ray 

 Society, to illustrate and advance our knowledge of the structure, the 

 morphology, and the physiology of these tribes of organisms. In doing 

 so, he was obliged to create a new nomenclature, which has now been 

 universally approved and adopted into biological literature. These 

 classes of animals are therefore entirely removed from the true radiate 

 Polypes. They are now known to Science as Hydrozoa and Hydroids, 

 and their position is fi:sed by certain relations with the Ascidian 

 Molluscs, to which, as I have said, they show close affinity. 



Nor is the interest of Dr. Allman's researches limited to the living 

 forms of animal life. I am informed by eminent geological authority 

 that he has also thrown new light upon some of the most obscure 

 questions of palseontology, and that the Graptolites of the Silurian 

 system, almost the oldest and most mysterious forms of palaeozoic 

 existence, are now known by Dr. Allman's investigations to have been 

 Hydrozoa. 



The extraordinary series of transformations exhibited by many of 

 these animals, in virtue of a process of alternate generation by 

 ovules and by buds, has been specially illustrated by Dr. Allman in 

 his " Monograph on the Hydroida " published by the Ray Society. 

 That the medusae, the sea nettles, which swim about our coast, and 

 which in their countless myriads light up with gleaming phospho- 

 rescence the darksome waste of ocean, should be but highly developed 

 buds of polypoid forms, must strike the scientific equally as the 

 popular mind with surprize and admiration. That such wandering 

 forms, endowed with powers of locomotion, with organs of higher 

 sense, with sight and hearing, of course in imperfect and rudimentary 

 condition, can be derived from a fixed polypoid base, that forms, 

 alternately sexual and non-sexual, can rise from a common source — 



K. I. A. MINUTES, SESSION 1877-8. rK"! 



