July 28, 1892] 



NA TURE 



305 



it cannot be said to lend very much direct support to the theory 

 now under discussion.^ 



Again, the choice of lesion in these experiments was a some- 

 what unhappy one. Epilepsy is a symptom which can be pro- 

 duced in a number of ways — its proximate cause, if there be a 

 single one, we are not as yet in a position to formulate. At- 

 tempts in this direction usually go no further than a vigorous 

 and often highly poetical description, in which metaphors 

 drawn from the phenomena of electricity are liberally employed. 

 It might have been more advantageous to have aimed at the 

 production of less equivocal symptoms, whose pathology is less 

 disputed — such, for example, as facial palsy. 



Lastly, we cannot exclude from these experiments the possi- 

 bility 01 the introduction into the system of chemical poisons or 

 even parasites, as incidental results of the operations. 



But this does not by any means exhaust our stock of in- 

 stances. The pages of pathology furnish us with more than 

 one group of important facts which satisfy all the conditions of 

 acquired characters. 



Chief among these stand those numerous modifications of 

 various organs which we regard, and rightly regard, from a 

 clinical point of view, as part of a given disease, but which 

 might perhaps be more correctly described as secondary ad- 

 justments made by the organism to meet certain primary morbid 

 changes induced in different organs by the disease itself 

 Such, for example, is hypertrophy of the heart consequent 

 upon valvular disease. Such hypertrophy is or is not a morbid 

 symptom accordmg to the point of view we happen to take. 

 I'rom the clinical standpoint it may be conveniently treated as 

 part of the disease. From the biological standpoint it is an 

 efitort on the part of the organism to adjust itself to altered con- 

 ditions brought about by the disease. It is certainly an acquired 

 character, in the strict sense of the term. 



An illustration will make this plain. Rheumatic fever is an 

 hereditary disease.'- Inflammation of the valves of the heart is 

 common in rheumatic fever, and hypertrophy of that organ 

 ollen follows as a consequent of this. But who would reckon 

 hypertrophy of the heart as forming part of a rheumatic in- 

 heritance ? It is true, no doubt, that whoso is heir to a 

 disease is heir by implication to all the biological incidents of 

 that disease. But he is not heir to them for the same reason. 

 The one belongs to him as the inheritor of a morbid tendency, 

 the other as the possessor of an organism. Diabetes, again, 

 is in some cases markedly hereditary. Secondary characters are 

 acquired in the course of this disease also; such as hypertrophy 

 of the bladder or stomach. But, however doomed from his 

 cradle to diabetes a peason may be, he is not born with an 

 hyperlrophied bladder and stomach. We should think it absurd 

 that such accommodations as these should be made before they 

 were wanted. If, then, we are right in regarding these as really 

 acquired characters — and it is difficult to see how we can avoid 

 so doing — it seems that pathology has here afforded us a sort of 

 crucial experiment. Of the morbid characters of which sundry 

 diseases are constituted, some are inherited, some are acquired — 

 the one are constantly transmitted, the others, so far as we 

 know, never are. 



But no one pretends that every disease is inherited. Con- 

 sider, for example, such a disease as lead-poisoning. Here, 

 there is not, obviously, any element of heredity. That two 

 people are not equally liable may be true enough ; that pre- 

 disposing causes exist is doubtless the case ; but that does not 

 prove an element of heredity. Predispositions may be themselves 

 acquired, as is the case in alcoholism. In such diseases as lead- 

 poisoning, we rightly stress the importance of the environment, 

 and minimize inherited tendencies. But such diseases will be of 

 little use to us here, unless two conditions are complied with. 

 The first is that they leave durable and definite lesions behind 

 them ; the second is that such lesions are not inconsistent with 

 the procreation of children. Of such lesions the familiar *' wrist 

 drop " of lead-poisoning may be cited as a good example. It 

 is often durable ; in not a few cases it is not cured ; it is not in- 

 consistent with the procreation of children. But there is no 

 evidence to show that this or kindred lesions are ever trans- 

 mitted. Facial palsy would be another instance, this malady 

 being often of considerable duration. This group of cases 

 constitutes another piece of negative evidence, not so import- 



• For other instances of supposed transmission of morbid characters arti- 

 ficially produced, see Zieglerand Nauwerck, "Pathology," vol. i. pp. 391- 

 92 ; Brown-S^quard's operations on eyes. Mison's on the spleen. 



' "Treatise on Medicine," by Fagge and Pye-Smith. Third edition, 

 vol. ii. p 694. 



ant as the last, because these cases are rarer, but still not 

 unimportant. 



It can hardly be disputed that these characters are acquired in 

 the sense under discussion. There must have been frequent 

 opportunuies of transmission, but we have no evidence of any- 

 thing of the kind. 



The general conclusion we have arrived at in this paper is 

 that pathology, so far from offering any support to the hypo- 

 thesis of the transmission of acquired characters, pronounces 

 against it. We have seen that it is possible to bring up a mass 

 of evidence, which seems at first sight to favour that hypothesis. 

 On further consideration, however, it becomes clear that only 

 a small portion of that evidence can be allowed to "rank." 



A considerable number of facts must be rejected, becau.se 

 though there can be no doubt that the morbid characters here 

 present are both acquired and transmitted, they are not acquired 

 in the sense under discussion — that is, by the somatic cells exclu- 

 sively—but by the entire organism. 



A considerable number of facts, again, meet with alike rejec- 

 tion, because there is no question that here certain morbid cha- 

 racters are transmitted, yet even supposing them to have been 

 acquired, it does not appear that precisely what was acquired is 

 transmitted, but something broader and more general. 



A considerable number of facts remain, which may be 

 allowed to " rank " as genuine instances of acquired characters. 

 These, if the hypothesis be correct, should be transmitted. But 

 of such transmission we find little or no trace. 



If we begin with scars and mutilations, even if the facts are 

 not all on one side, the balance of evidence is decidedly against 

 the hypothesis. If we appeal to the results of experimental 

 research, the question is more open ; but if the hypothesis does 

 not encounter quite so decided an opposition in this quarter, it 

 can scarcely be said to derive much support there. 



If we pass into the main region of pathology, we have to use 

 some circumspection in looking about for instances which shall 

 be genuine examples of acquired characters. That such in- 

 stances really exist it has been our endeavour to show, notably 

 in those secondary characters which organisms acquire by way 

 of accommodating themselves to the effects produced by disease. 

 So far from being rare or recondite, these constitute a group of 

 familiar and well-ascertained facts. If transmission has not 

 occurred, it cannot be for want of opportunity — there must have 

 been scores of such opportunities. That it has not occurred, 

 constitutes a piece of very important evidence against the 

 hypothesis under discussion. HenRY J. Tylden. 



A TRIP TO QUEENSLAND IN SEARCH OF 

 CERA TODUS> 



IV/r V main object in going to Queensland was to procure, if 

 possible, the eggs of Ceratodus and the creature itself ; 

 secondly, I wanted to collect earthworms ; and, thirdly, to see 

 the country. In my main object I was quite unsuccessful, for 

 the simple reason that this year Ceratodus did not lay its eggs 

 till late on in November — two full months later than the time 

 recorded by the only observer who had up till then procured 

 them. University work forced me to return, not by any means 

 empty-handed, but without the one thing which had tempted me 

 to go north. 



To save time, and avoid unpleasantness also, I went by train. 

 It is a long weary ride across New South Wales, especially 

 in warm weather. Unfortunately I left Sydney by the northern 

 mail on Friday evening. There were very few carriages, and 

 some of what there were were "engaged" for legislators who 

 travelled home free and in ease whilst we who paid for our 

 journey were huddled and crowded together. This discreditable 

 state of affairs seems to be common at the close of each week 

 during the sitting of Parliament in Sydney. 



The journey north leads by the side of the Hawkesbury River, 

 and after passing across the well-known bridge the train skirts 

 the shores of what appears to be a succession of lakes. In 

 reality, the winding river, shut in by wooded hills, expands every 

 now and then into sheets of water, each of which in the gather- 

 ing darkness seemed to be a little lake. About eleven o'clock 

 you find yourself apparently running along through the streets of 

 Newcastle, and stretching out eastwards see the long quays and 



» P.iper read by Prof. W. Baldwin Spencer, before the Field Naturalists' 

 Club at Victoria, on March 14. Reprinted'from the \''ictorian Naturalist 

 for June and July. 



NO. II 87, VOL. 46] 



