1869.] Biology. 605 



Primulas, in which the style and stamens were either both long or 

 both short — a fact difficult to account for on the theory of reversion, 

 as both could not be the original form. 



The Eev. A. M. Norman then read an account of the recent 

 successful dredgings in the 'Porcupine,' in a letter from Professor 

 Wyville Thomson, prefacing it with a sketch of what had been 

 abeady done in deep-sea dredging. In the first excursion this 

 season Mr. Gwyn Jeffreys had dredged in 1472 fathoms ; but Pro- 

 fessor Wyville Thomson, finding the weather very fine, proceeded to 

 the deep water off' the Bay of Biscay, and succeeded in bringing up 

 li cwt. of ooze from the enormous depth of 2435 fathoms, with a 

 bottom temperature of 36°'5 Fahr. Subsequently, at 2090 fathoms, 

 2 cwt. of chalk-mud was brought up. These dredgings contained 

 a fine Dentalium and other mollusca, crustaceans, annelids, crinoids, 

 and starfishes, demonstrating the existence of all the higher forms 

 of marine life in the deep abysses of the ocean. The dredge was 

 down three hours. From careful temperature observations it was 

 found that the effects of solar heat did not reach farther than 20 

 fathoms, while some other extraneous source of heat, probably that 

 of the G-ulf-stream, was detected as far as 500 to 700 fathoms; after 

 ■that the temperature decreased 0°*2 for each 200 fathoms, which was 

 probably its normal rate. The deep water was analyzed, and found 

 to contain an excess of oxygen and of organic matter, thus explain- 

 ing the source whence the living jelly of the ooze, Bathyhius, derived 

 its nourishment. 



In from 500 to 700 fathoms water Cidaris was abundant, as 

 well as vitreous sponges in great variety and of many new types, 

 and organisms allied to Yentriculites, thus exhibiting a series of 

 forms strikingly similar to those characteristic of the true Chalk 

 formation. As this chalky ooze was now known to extend over 

 the bed of all the great oceans, it was a fau^ presumption that 

 this peculiar substance had been forming continuously, somewhere 

 or other, from the Cretaceous epoch to the present day; and as 

 many of the characteristic forms of the chalk (although of dis- 

 tinct species) were proved to be still in existence, it was very 

 possible that some of the chalk deposits of the globe might be 

 of various intermediate ages between the Cretaceous and recent 

 epochs. 



Professor Huxley, Dr. Hooker, and Dr. Percival Wright took 

 part in the discussion, the former adverting to the immense interest 

 of the discovery that the direct descendants of chalk fossils were 

 now in existence almost unchanged ; and Dr. Hooker claiming that 

 Captain Pioss's Antarctic dredgings had first demonstrated the 

 variety and abundance of deep-sea life, and had disproved Edward 

 Forbes' celebrated theory even before it had appeared. 



