444 



GENERATION. 



junctions and ceremonies relating to marriage 

 arid concubinage, are to be regarded rather as a 

 picture of the state -of civilization among the 

 different people to which they have belonged, 

 and as the result of local situation and circum- 

 stances, than a consequence of their physical 

 organization or natural endowments, as some 

 would have us to believe. But the considera- 

 tion of these modifications in the customs and 

 habits of different nations belongs more appro- 

 priately to the province of the political econo- 

 mist than of the physiologist. 



4. Relation of' reproduction to the brain. 

 In how far the sexual feelings just spoken of, 

 and the reproductive function as a whole, are 

 connected with the brain or any of its parts, we 

 leave to be discussed by others. We shall only 

 remark in this place respecting this connection, 

 that the mental feeling and local affection rela- 

 ting to sex are very intimately associated toge- 

 ther; on the one hand, the local irritation of 

 the genital organs exciting mental desire, and 

 on the other, the erection and other signs of 

 affection of the sexual organs being immediately 

 caused by all those ideas and passions of the 

 mind which bear a relation to sex. In the 

 same manner as the action of the heart, the flow 

 of the blood in some of the bloodvessels, the 

 processes of digestion, respiration, and secre- 

 tion are modified by mental emotions, the sexual 

 function may be regarded as subject to their 

 influence, and consequently subject to modifi- 

 cation from the condition of the mind or brain. 



In the phrenological system, as is well 

 known, it is held that the cerebellum is 

 that particular part of the encephalon which 

 presides over the sexual function, in other 

 words, that sexual feeling belongs to the cere- 

 bellum as its sensorium commune, to which 

 impressions of a sexual kind proceed, and from 

 winch -emanates sexual desire, as well as the 

 influence under which the reproductive organs 

 execute their appropriate functions. The proofs 

 alleged in favour of the phrenological hypothesis 

 are principally of the following kind : 1st, that 

 the back of the head and neck, and particularly 

 the cerebellum, is largest in those of the human 

 species who shew much sexual love, and among 

 animals in those in which sexual feeling and 

 productive power are greatest; 2d, that local 

 affections of the genital organs, and variations in 

 the degree of sexual desire, frequently coincide 

 with congenital deviations from the natural 

 form and structure of the cerebellum, and 

 morbid organic changes of that organ, such 

 as inflammation, suppuration, effusion, tu- 

 mours, and softening, or violent injuries, such 

 as wounds producing the destruction or re- 

 moval of portions of the same part of the 

 brain.* W leave to others the examination 

 of the truth of this view, observing merely 

 that we are not inclined to adopt the hypo- 



* The proofs of the connection of the cerebellum 

 with the sexual function may be more fully stated 

 as follows: 



1st. The coincidence of barrenness or impotence 

 with hydrocephalus, ramollissement, suppuration, 

 or wounds of the head, and in particular of the 

 back part and cerebellum. 



thesis as already established upon sufficiently 

 accurate or extensive data ; and we would re- 

 mark that the comparative anatomy of the 

 brain (in which, rather than in experiments on 

 animals, we should feel disposed to place much 

 reliance, from the acknowledged difficulty 

 of making correct deductions as to function 

 from the effects of morbid alteration or artificial 

 injury of the encephalon) affords very few argu- 

 ments in favour of the view now alluded to, and 

 furnishes several facts which militate strongly 

 against it. 



5. Distinction of species. Mules. The in- 

 stinctive feelings which lead to the union of 

 male and female animals of the same species 

 may be looked upon as one of the means pro- 

 vided by nature for the distinct preservation of 

 each specific race. So general indeed is the 

 law that animals of one species propagate with 

 one another only, that, as we already remarked, 

 this circumstance alone has been adopted by 

 some as the true specific character. We shall 

 see reason, however, to doubt its sufficiency. 



While the natural repugnance which the 

 males and females of different species or 

 genera have to propagate together may be 

 regarded as one of the most powerful means 

 by which the distinction of species is insured, 

 we must not lose sight of other circumstan- 

 ces which contribute to the same effect. 

 Among these may be mentioned, in the first 

 place, the unfruitf'ulness which generally attends 

 the union of different species when it has oc- 

 curred ; then the difference in the size of ani- 

 mals, the discordant properties of the semen of 

 the one and ova of the other, the difference of 

 season at which nearly allied animals come 

 into heat, as well as many other circumstances 

 which put a bar to the extension of races by 

 promiscuous propagation of species or genera. 



In the state of domesticity, however, this, 



2d. The coincidence of excited states of the re- 

 productive organs, as priapim, nymphomania, and 

 satyriasis, with inflammation of the same parts. 



3d. Instances occurring in birds (mentioned by 

 Serres) of cerebellar apoplexy from the persistence 

 of unsatisfied sexual desire. 



4th. Coincidence of cerebellar apoplexy, inflam- 

 mation, &c. and diminution of the sensorial power, 

 with over-exertion of the sexual powers, excess in 

 venereal pleasures, &c, 



5th. Large size of the cerebellum or upper and 

 back part of the neck in those individuals among 

 the human species or among animals in which the 

 sexual desire and reproductive power are greatest. 



6th. The reverse being the case in those in whom 

 the function is inactive ; as the small size of the 

 back of the neck, &c. in castrated animals. 



In endeavouring to ascertain the value of this 

 kind of evidence adduced in favour of the phrenolo- 

 gical view, we must consider well the nature of the 

 alleged facts themselves, and weigh them candidly 

 against facts of an opposite tendency adduced on 

 the other side, such as those cases of small size or 

 absence of the cerebellum, in which the sexual 

 propensities have been highly developed, and the 

 converse cases ; and we must, at the same time, 

 not lose sight of those other experiments and obser- 

 vations which would tend to shew either that the 

 cerebellum is intimately connected with other func- 

 tions than the reproductive, or that the sexual 

 powers are influenced by the condition of other parts 

 of the brain besides the cerebellum. 



