Miscellaneous. 305 
red in Great Britain. Mr Carpenter read an abstract of Dr Pritcliard's views 
contained in his " Physiology of Man," respecting the proper criterion upon which 
zoological and botanical species should be founded. He considered that science 
had now attained to that state in which it had become evident that a discrimina- 
tion of species could not repose upon external characters alone, and ought to be 
coupled with certain characteristics, which could not be entirely obliterated or 
altered by the influence of external causes. He more particularly specified four 
heads, under which many circumstances might be arranged, as auxiliary means for 
the determination of specific differences. 1st, Such as regarded the several vital 
functions, because there were minute differences of structure which could only 
be understood to exist by observing a difference in the results produced by the 
same functions in different individuals. 2rf, Hybridity. Dr Pritchard considered 
that true hybrids could only be rendered fertile by mixing with the parent breed. 
3d, He thought it possible that pathological considerations might be employed, 
and instanced the operations of morbid poisons. 4th, The instincts, habits, and 
what might be called the psychical endowments of particular animals. The ab- 
stract given by Mr Carpenter was intended to promote a discussion on a subject 
already treated of by Dr Pritchard, and for which we may refer to his work. 
Mr P. Duncan thought that instinct and habit were of great service in settling 
specific distinctions, and noticed particularly the difference in nidification be- 
tween certain species of birds which very closely allied. 
Mr Eyton mentioned having obtained fertile hybrids between a common gan- 
der and the Anas cygnoides. Also between the Chinese boar and a common pig. 
Mr Vigors was inclined to take Hunter's view of the non-fertility of true hybrids, 
and thought that many supposed exceptions had originated in a want of proper 
caution in performing the experiments. He thought with Dr Pritchard, that the 
diseases of different animals might be taken as one means of discriminating spe- 
cies, and he considered it possible to make use of the distinctions between the 
parasitic animals which infested them. Dr Riley differed from Dr Pritchard, and 
considered his views as too metaphysical, and thought it would one day be found 
necessary to abolish the notions of species altogether. 
Mr Yarrell believed it to be nearly a universal law that hybrids were barren. 
It was unquestionably the case with the common mule, as had been often proved 
on the continent, where this animal was largely bred. But he mentioned an in- 
stance where fertile hybrids were produced between Anas boschas and acuta. 
Rev. Mr Phelps read a paper " on the Formation of Peat," particularly describ- 
ing some peat tracts south of the Mendip hills. So long as this tract had con- 
tinued to be well drained, whilst it belonged to the abbots of Glastonbury, it af- 
forded a very rich pasture land. After the monastery was suppressed, it became 
crown-land, and was neglected, and soon returned to the state of a peat bog. It 
had been subsequently reclaimed a second time, and Mr Phelps's researches had 
enabled him to find trees which had flourished during the period it was under the 
power of the abbots, and which had been imbedded in the subsequent formation 
of the peat ; as well as many other objects of interest, and among these were some 
Roman remains which he had obtained at a depth of twelve feet. 
Mr Mackay, after exhibiting some specimens of Scotch pine which he had pro- 
cured from peat bogs in Ireland, proceeded to read a communication from Mr 
Nuttall " on the Management of the Pine Tribe," in which he stated having lop- 
ped some larches down to a strong lateral branch, and these had nevertheless be- 
