Genus Comatula. 



Memoir on the Star-Fish of the genus Comatula^ demonstrative of the 

 Pentacrinus europceus being the young of our indigenous species. 

 By John V. Thompson, F.L.S., Deputy Inspector-Greneral of 

 Hospitals. Communicated by Sir James M'Grrigor, F.R.S. * 



[Extracted from Jameson's Edinburgh New PhUosophical Journal, vol. xx., p. 295.3 



" If we were told by any traveller that he had visited an unknown 

 region, where the animals dropt their eggs on trees and shrubs, which 

 there fixed themselves and shot up like parasitic plants on a long stem, 

 gradually evolving, at their extreme end, member after member and 

 function after function, until the young animals became so perfect 

 as to resemble their parents in every essential point, — when their 

 attachment to the connecting foot-stalk was dissolved, and they 

 became free and locomotive, and betook themselves to the wandering 

 life of the parent stock ! few could be got to believe facts so incredible, 

 and so much at variance with the course of nature, as made manifest 

 everywhere and from all time ; but if established on incontestable 

 evidence, the highest degree of surprise and admiration would neces- 

 sarily supplant our incredulity, — voyages would be undertaken, and 

 the curious of every country would flock to witness such an extraor- 

 dinary anomaly, at the greatest risk and expense. If, then, a fact so 

 contrary to our experience relating to the superior classes of animals 

 should be capable of exciting so great a degree of interest, it may be 

 presumed that an analogous circumstance, now for the first time 

 actually discovered in an animal belonging to one of the inferior 

 classes, must be considered at least as highly worthy of the attention 

 of the philosophic naturalist. 



"It is no uncommon thing, in the inferior classes of the animal 

 kingdom, to find animals permanently attached from the period of 

 their birth, and during the whole time of their existence, familiar 

 examples of which we have in the oyster, anomia, and various other 



* Read before the Royal Society of London, in June, 1835. 



