572 Proceedings of Societies. [ September, 
motion the common Claytonia Virginica and some buttercups were fer- 
tilized by their own pollen. The fertilization of these plants had been 
somewhat of a mystery to him, as in view of some prevailing theories 
of cross fertilization by insect agency, these plants ought not to be self 
fertilized, but from repeated observations he was satisfied that no insects 
had visited plants that had yet seeded abundantly. The process of fer- 
tilization in Claytonia and Ranunculus, independent of insect agency, was 
described minutely. 
ants of course had peculiar functions to perform, and there were 
pre-ordained plans and special arrangements through which these func- 
tions are exercised. But the workings of plant life are so complicated 
that though we see certain results follow certain movements, we are not 
always sure that we perceive the great and deeper object arrived at in 
the order of nature. Hence arose the differences of opinion prevailing 
in regard to the object of cross fertilization. Some plants had arrange- 
ments which seemed to preclude the possibility of self-fertilization, and 
the assumption followed that nature abhorred close breeding in plants 
and specially designed such structures to secure the plant against it. 
He believed that nature had a deeper purpose, as yet unknown, and 
chiefly because of such instances as he had given this evening, where 
nature could not abhor close breeding, when the result of the “sleep 
of plants” was most perfect in securing self-fertilization. 
May 23d. Dr. Leidy observed, in continuation of his remarks of the 
previous meeting, on the extinct animals of the Ashley phosphate beds 
of South Carolina, that they are remarkable for the multitude of remains 
of fishes which they contain, especially of sharks and rays. Among the 
former were the giants of their kind, the Carcharodon megalodon and 
C. angustidens. A tooth exhibited of the megalodon shark is five and a 
half inches long and four and a quarter inches broad at the base. The 
living white shark, pertaining to the same genus, reaches upward of 
thirty-five feet in length, and has teeth two inches in length. Supposing 
the megalodon shark to have reached the same proportions in relation 
with the size of the fossil teeth, it must have exceeded seventy feet m 
length, and must have proved the most formidable monster of the 
ancient ocean. 
Another specimen presented for the inspection of the members is @ 
knob of bone, such as is found at the root of the tail of the devil-fish, 
the largest of the existing rays. In the latter the bone is the only one 
of the body, and it supports a minute spine, a mere rudiment of the 
barbed weapon of the sting-ray. Our devil-fish, of which a pee 
was once exhibited in Peale’s Museum, of this city, reaches a breadth 
eighteen feet, with a length of about fifteen feet. The fossil bon 
though the only thing left to tell the tale of its former possessor, 18 nit 
? characteristic specimen. It is of more robust proportions than t 
its living representative, and probably indicates an extinct species, for 
which the name Ceratiptera unios was proposed. 
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