July 25, 1889] 



NATURE 



503 



room on an iron support of two stories, provided with the 

 necessary discharge-pipes to carry off the water that has 

 circulated in the aquariums. Against the shortest wall, 

 opposite that in which the door is placed, there is a table 

 covered with porcelain for chemical manipulations. Above 

 this table there is a reservoir of fresh water. In the 

 middle of the room, behind the support of the aquariums, 

 are two tables covered with marble. Against the wall 

 opposite the window are the shelves for the instruments 

 and for the collections. One corner is set apart for the 

 principal fishing implements. 



The station has a boat, the i?r7;/<'//z<i;, that serves for 

 short excursions, and for researches in shallow water. 

 The fishing implements consist principally of trawl- 

 nets for the depth, nets for surface fishing, apparatus 

 for extracting masses from the bottom, sieves, nets, 

 harpoons, &c. These implements have been made ex- 

 pressly at Naples, under the supervision of Dr. Paolo 

 Mayer, of the Zoological Station. 



The station is also provided with numerous aquariums 

 for study, and with the necessary chemical apparatus. 

 The library is limited to the more common and useful 

 treatises, and to a certain number of memoirs concerning 

 the marine fauna. 



We hope that even by these simple means it will be 

 possible to obtain satisfactory results. Many important 

 works on marine zoology have been produced far away 

 from zoological stations under less favourable conditions 

 than those of our little station. 



L. Camerano. 

 M. G. Peracca. 



Zoological Museum, Turin. D. Rosa. 



WEISMANN ON THE INHERITANCE OF 

 INJURIES.-' 



T N an address to the Naturforscher-Versammlung at 

 ■*• Cologne, last autumn (now published in a compact 

 pamphlet of fifty-two pages), Dr. Weismann examined 

 the evidence for the inheritance of injuries. In earlier 

 works he has shown that the facts of organic evolu- 

 tion can be explained without the hypothesis of the 

 inheritance of acquired characters, and his theory of the 

 germ-plasma as the basis of heredity is hardly com- 

 patible with the traditional and Lamarckian view. The 

 supporters of the old view have laid great stress upon 

 the transmission of the effects of injuries. A great many 

 of the cases relied on rest on merely anecdotal evidence, 

 and Weismann examines and dismisses many types 

 of them. Such, for instance, is the case adduced by Dr. 

 Zacharias, and quoted by Eimer, of a tailless cat which 

 produced tailless kittens. Nothing whatever of how the 

 mother lost her tail is -known, and nothing is known of 

 the father. Tailless kittens appearing suddenly in vil- 

 lages have been traced, more than once, to an imported 

 male of one of the many tailless breeds. In any par- 

 ticular case, it is as logical to refer the appearance of 

 tailless kittens to a hypothetical mutilation of the mother, 

 as it would be to deduce from the many-toed Oxford cats 

 that Mr. Poulton had fixed additional toes on the paws 

 of their ancestor ! 



Weismann made an elaborate series of experiments on 

 mutilation. On October 17, 1887, he had the tails re- 

 moved from seven female and five male white mice. On 

 November 16 the first brood appeared. These, and all 

 subsequent broods, were removed from the cage. Up to 

 December 17, 1888, 333 young were born, and in none 

 of them was there any sign of the mutilation being in- 



"Ueber die Hypothese einer Vererbung von Verletz'inE^en." Von Dr. 

 August Weismann, Professor in Freiburg i. Br. (Jena : Gustav Fischer, 

 1889 ) 



herited. In cage 2, fifteen young, of December 2, 1887, 

 were placed, their tails having been removed. These, up 

 to December 17, 1888, produced 233 young, all with 

 normal tails. In cage 3, fourteen young of the second 

 generation, with tails removed, were placed ; and up to 

 December 17, 1888, they produced 141 young, all quite 

 normal. The experiment was carried, with a negative 

 result, down through five generations of mutilated ani- 

 mals. The length of tail of new-born mice varies from 

 io"5 millimetres to 12 millimetres. In the series of 

 experiments, 849 young were produced by mutilated pro- 

 genitors, and in no case was a mouse produced with its 

 tail less than io"5 millimetres. 



The author points out that, while it might be said that 

 experiments through a far greater number of generations 

 were needed, the so-called cases of inheritance of mutila- 

 tion all imply that the mutilation is impressed on the 

 immediately following generations. A mother breaks 

 her finger, and her daughter has the joint of the corre- 

 sponding finger imperfect. A cow has her horn torn off, 

 and, in due course, gives birth to a one-horned calf. 



Moreover, there are many cases of mutilations which 

 have been made for hundreds of years without result. 

 For instance, Settegast shows that all the crows but the 

 rook have bristly feathers on their beaks. Rooks, too, 

 have these feathers while nestlings ; but, later on, they 

 lose them by perpetually pushing the beak into the 

 ground in search of food. 



There are a great many cases which at first sight ap- 

 pear to prove the inheritance of injuries. As an example 

 of how easy it is to be deceived, Weismann relates that 

 a friend had a vertical scar (with comb-like strice) on the 

 left ear, the result of a sword-wound. On the left ear of 

 this gentleman's daughter was a curiously similar mark- 

 ing. But it was ultimately noticed that on the right ear 

 of the father was an appearance precisely similar to that 

 on the left ear of the daughter. On closer examination 

 of the father's left ear there was seen, under the scar, a 

 linear streak, from which the stria; ran, forming a comb- 

 like structure. It was this, doubtless a congenital varia- 

 tion, and not the accidental scar, that the daughter had 

 inherited. 



It is impossible to give, by extracts, an adequate con- 

 ception of Dr. Weismann's ingenious analysis and mas- 

 terly collation of evidence. There is enough in it to 

 satisfy the most conservative of biologists (at least with- 

 out a theory) that the transmission of injuries must be 

 handed for ever to the " scientific novelist " and the jaded 

 melodramatist. With them it may flourish, and rescue 

 many a doubtful heir, and secure the happiness of many 

 a heroine in the third volume, or before the curtain falls. 



It is not so certain that all will admit Weismann's con- 

 tention that the demolition of the inheritance of injuries 

 furnishes strong presumptive evidence that acquired cha- 

 racters are not inherited. It might well be urged that 

 there is a great distinction between characters which are 

 obviously not useful (such as injuries) and useful charac- 

 ters. It is clear that if acquired characters are inherited 

 it would be of the highest utility if the inheritance were 

 selective. The tiny piece of ancestral germ-plasma in- 

 creases exceedingly during the ontogeny. Has the dis- 

 tinction between germ-plasma and somatic plasma passed 

 sufficiently out of the region of theory to let us infer, 

 from the non-reflection of injuries during the process of 

 growth, that all acquired characters are not reflected ? 

 Can we hold that, were acquired characters reflected, 

 injuries too must be reflected? It is a question, on the 

 one hand, of the nice adjustment of fine probabilities ; 

 on the other, of elaborate, long-continued, and specially 

 directed observation. But, whatever is the final answer 

 of science, this essay will be not the least of the author's 

 many valuable contributions to it. 



P. C. M. 



