MAKCH 16, 1900.] 



SCIENCE. 



435 



slide finally came to rest, Here a few trees 

 that were left standing are deeply scarred 10 

 or 15 feet above the ground where they were 

 struck by trunks that were carried forward over 

 deep snow. A number of excellent heliotype 

 views are given of the mountain, the frontis- 

 piece being particularly fine. 



W. M. Davis. 



ZOOLOGICAL NOTES. 

 BEGBNEEATION AND LIABILITY TO INJURY. 



In a recent number of the Anatomischer An- 

 zeiger, Professor T. H. Morgan gives an account 

 of his later experiments on the regeneration of 

 the appendages of the hermit-crab. It will be 

 remembered that his first experiments, made at 

 Woods Hole in 1898, showed that certain ap- 

 pendages, because of their protection within the 

 mollusk shell in which the crab lives, regenerate 

 after artificial amputation quite as readily as the 

 more exposed appendages which in nature are 

 constantly liable to injury, and which actually 

 reveal a much higher percentage of injuries. 

 This result was clearly at variance with the 

 opinion of those who believe that there is a 

 definite relation between the regenerative ca- 

 pacity of a part and its liability to injury. 



Professor Weismanu attempted to explain 

 the phenomenon by attributing to the more or 

 less protected appendages of the hermit-crab 

 the inherited regenerative power of some re- 

 mote ancestor — an ancestor which was not domi- 

 ciled in a shell. Moreover, he thought the fact 

 that the power of autotomy was possessed by 

 the three anterior thoracicappendages — parts 

 frequently subject to injury — and not possessed 

 by the two protected posterior pairs, was evi- 

 dence of the comparatively recent origin of auto- 

 tomy, and the more remote origin of regenera- 

 tion, Morgan having shown that the fourth and 

 fifth pairs of legs do regenerate. In stating 

 that " The adaptation for autotomy once gained, 

 the power of regeneration had of necessity to 

 become localized ; that is to say, the apparatus 

 necessary for it had to be transferred to those 

 parts at which alone the breaking off of the 

 the limb occurs," Professor Weismann gave, 

 to use his form of expression, a new lead which 

 Morgan has again followed in his series of ex- 

 periments of the summer of 1899. These ex- 



periments show that the power of regeneration 

 has not become localized, and that the first 

 three thoracic legs can regenerate both when 

 cut off proximal to, and when cut off distal to 

 the breaking-point of autotomy. Moreover, 

 the experiments of Morgan incidentally give 

 additional reasons for his earlier conclusion 

 that there is no relation between regeneration 

 and liability to injury, for in removing the ap- 

 pendages, at a point proximal to the ' breaking- 

 joint,' he laid bare a regenerative zone, which 

 in a state of nature must almost never be called 

 upon to exercise the function of repair. 



Weismann's suggestion that in the last ab. 

 dominal appendage the regenerated part would 

 be renewed after the pattern of a tail fin of the 

 Macroura, rather than after the original pat- 

 tern of a 'holdfast,' is shown not to be sup- 

 ported by the facts. 



H. C. B. 



COMFORT AND PBODVCTIVITY. 

 M. Max Gerard, in the Bulletin Scientifique, of 

 the University of Liege, January, 1900, shows 

 the influence of the compensation of the work- 

 man upon the productivity of establishments, 

 taking his data from Dechesne, Ansiaux, and 

 Waxweiler. He places the values of services 

 and products, as reported from the several coun- 

 tries, in certain cases, thus : 



Wages Value of product; 



per diem. Labor per tonne. 



United States 12.20 fr. IT.l.'i fr. 



Great Britain 6.25 " 15.15 " 



France 4.15 " 16.90 " 



Belgium 3.20" 10.50 " 



It is thus found that the cost of the product 

 is, as a rule, very slightly affected, in these dif- 

 ferent countries by the wages paid their work- 

 men, and France, paying one third the wage 

 given in the United States, finds the product to 

 cost practically the same amount. Great Brit- 

 ain, paying one-half the wages paid in the- 

 United States, produces very little more cheaply. 

 Belgium pays little more than one-fourth the 

 wages rnliug in similar establishments in Amer- 

 ica and the product costs two-thirds as much, 

 and even this difference may be due, in some 

 degree, to other conditions. 



The author of the paper accounts for these 

 facts by the interaction of wages and morale, 



