APPENDIX. 



I. ON PHRENOLOGY. 



WITHOUT entering into a general discussion of the merits of the system of Phrenology at 

 present in vogue, which would be misplaced in a Treatise like the present, the Author feels 

 it desirable to express the opinion, which a recent careful examination of the chief questions 

 at issue between Phrenologists and their opponents have led him to entertain. 



That the different portions of the Cerebral mass should have different parts to perform in 

 that wonderful series of operations, by which the Brain as a whole becomes the instrument 

 of the Mind, does not seem to him in the least improbable. Nor, if we duly consider the 

 general plan of construction of the nervous centres in Vertebrated animals, is it a legitimate 

 objection to such a view, that there is no mechanical distinction of "organs" either upon 

 the surface or in the interior of the Cerebrum ; for in the Spinal Cord and Medulla Oblon- 

 gata, there is a continuous tract of grey matter, which is really made up of an assemblage of 

 ganglia having dissimilar functions, although there are no external indications of the dis- 

 tinctness of these ganglia. Further, it appears to be quite legitimate to judge of the com- 

 parative powers of different parts of the Cerebrum, or of the same portions in different in- 

 dividuals, by their comparative sizes; due allowance being made for other circumstances of 

 difference. And if the development of a particular part of the Cerebrum were constantly 

 found to be in harmony with the manifestation of a certain feature of psychical character, 

 there would be strong ground for regarding such a part as the instrument of the mental 

 operation in question. The attempt to establish a system of Cerebral Physiology by com- 

 parative observations of this nature, appears to the Author, therefore, a most legitimate one ; 

 and his objections to the present system of Phrenology are based only on the very imperfect 

 manner in which it has been constructed ; the foundations on which it rests being (in his 

 opinion) of a veiy insecure character; and the superstructure having been built up of the 

 slightest possible materials. The following are the chief points on which he feels called 

 upon to express his dissent. 



1. The present system of Phrenology is founded only on comparative observation of the 

 psychical character and cerebral conformation in different individuals of the Human species 

 alone; evidence derived from Comparative Anatomy being admitted only so far as it corre- 

 sponds with the system thus constructed. When the fundamental importance of the study 

 of Comparative Anatomy in the determination of the functions of all other organs, and of 

 other parts of the Nervous System itself, is duly considered, the Author cannot regard any 

 system of Cerebral Physiology as having a claim to a place in a scientific treatise, which is 

 not founded on this basis. 



2. The present system of Phrenology is altogether inconsistent with well-ascertained facts, 

 regarding the Comparative Anatomy and Embryological Development of the Cerebrum. It 

 is clearly established by anatomical research, that the posterior lobes of the Cerebrum are 

 relatively much smaller in the Quadrumana than they are in Man, and that they disappear 

 altogether in the Carnivora, not a vestige of them being discoverable in any of the lower 

 Mammalia ; and that the middle lobes, though they may be traced in the lowest of the Mam- 

 malian Class, are altogether wanting in Birds, Reptiles, and Fishes. The Cerebrum of these 

 animals, therefore, is the rudiment of the anterior lobe only of that of Mammalia. Further, 

 it has been lately shown by Prof. Retzius (whose researches on this head are confirmatory 

 of those of Tiedemann, at the same time being more full and precise), that the development 

 of the Cerebrum of the Human Embryo takes place on the same plan. In the first period, 

 which corresponds with the second and third months, only the anterior lobes form ; in the 

 second period which is comprised in the end of the third month, in the fourth, and in a 

 small portion of the fifth, the two middle lobes appear; and it is not until the latter part of 

 the fifth month, that the development of the posterior lobes properly commences. They 

 sprout, as it were, from the posterior extremity of the middle lobes; from which they are 

 divided, on the brain of the mature foetus, as well as, occasionally in that of adults, by a dis- 

 tinct furrow. The exact mutual confirmation afforded by these two sources of knowledge, 



