June 5, 19 13] 



NATURE 



349 



free from moisture by the heat supplied from within, 

 and is therefore always in a suitable state for produc- 

 ing electricity by friction against metals or other 

 substance. It is obvious that the corpuscles shot off 

 from the glowing filament and sticking to the inside 

 of the bulb can have little or no part in the production 

 of such high potentials, for the very greatest speed 

 they could acquire would be that corresponding to the 

 voltage of the supply mains. A glass tube filled with 

 hot mercury can, in fact, be used as successfully as 

 the lamp. 



This lamp method of producing electricity by fric- 

 tion is so easy to employ, and, moreover, so certain in 

 action (the degree of electrification can be regulated 

 to a nicety), that it is bound to be of interest to users 

 nf electroscopes. R. YVhiddington. 



Naid or Tubificid? 



In Nature for November ib, 1911 (p. 78), I directed 

 attention to the fact that a tiny annelid known as 

 Rhyacodrilus had been found in England, and that 

 it differed in some respects from the specimens re- 

 corded for Switzerland. Some difficulty was experi- 

 enced by the Continental authorities in assigning it 

 a place. Ditlevsen contended that it belonged rather 

 to the Naididse than to the Tubificidas, but Michaelsen 

 in his various publications refers it to the latter. In 

 his " Siisswasserfauna Deutschlands " he specially dis- 

 tinguishes those annelids which reproduce by fission 

 from those which form cocoons, and places the 

 Naididse in the former group, while the Tubificida? 

 are relegated to the latter. Then he places Rhyaco- 

 drilus ( = Taupodrilus) among the Tubificidae, because 

 it is possessed of sexual organs. 



Aided by a Government grant for the study of anne- 

 lid bionomics and economics, I have just been able to 

 make an interesting discovery. Rhyacodrilus is found 

 in our midland streams, and in the summer is 

 possessed of alj the organs belonging to the Tubificids. 

 In the winter and spring, however, it adopts the 

 Naid method of reproduction, and forms a chain 

 (Tierkette). It is therefore a link between the two 

 families, and the question arises : To which does it 

 most certainly belong? I favour the Naid association. 



Swadlincote, May 16. Hilderic Friend. 



WORK OF THE EUGENICS RECORD 

 OFFICE. 

 T3ROF. DAVENPORT and his staff of 

 •*■ collaborators and "field" workers have 



shown great activity in the collection of family 

 histories. The two first of a series of quarto 

 memoirs, beautifully printed at the expense of 

 Mr. Rockefeller, and published by the Eugenics 

 Record Office, contain elaborate accounts of the 

 members of two particular stocks whose claim 

 to lame resembles and rivals that of the Jukes. 

 The "Hill Folk," whose relationships with one 

 another and with their common ancestry were in- 

 vestigated by Miss Danielson, comprise more than 

 700 persons all descended from two particular 

 individuals who settled near a New England town 

 in about the year 1S00. Elaborate calculations 

 as to their cost to the town and State for 

 aid as paupers and for maintenance in prisons 

 and institutions reveal the fact that these charges 

 are constantly and rapidly increasing. Feeble- 

 mindedness, alcoholism and the evils which spring 

 from each or both in combination are terribly 

 NO. 2275, VOL. 91] 



prevalent among them, and their distribution 

 within the families is clearly shown in the 

 extensive pedigree charts which embellish the 

 memoir. 



Although Prof. Davenport does not claim that 

 the material here collected is of a kind suitable for 

 the study of inheritance, it is of interest to note 

 that from it he propounds a theory on the trans- 

 mission of feeble-mindedness of a kind very 

 different from that suggested by himself and Dr. 

 Weeks in their paper "A First Study in Inherit- 

 ance of Epilepsy " (Eugenics Record Office, 

 Bulletin No. 4, 191 1). 



According to his earlier view, feeble-mindedness 

 and epilepsy are both due to the absence of a 

 gametic factor the presence of which is necessary 

 for normal development. They are thus trans- 

 mitted as a simple recessive character which might 

 appear in either or both of these forms. 



The material collected in the memoir under 

 review, when analysed, gives results quite incom- 

 patible with this theory, and another and more 

 complex one is consequently suggested. In the 

 latter, which is propounded not as a dogma, but 

 as a tentative hypothesis, different types of feeble- 

 mindedness are taken into consideration, and it 

 is supposed that each depends on the absence of 

 a separate factor. Thus when two feeble-minded 

 persons whose defect is of the same type are 

 mated together, all their children will reproduce 

 it, but where the type of mental defect of one 

 parent is different from that of the other, none of 

 their children need necessarily be feeble-minded 

 at all. 



The second memoir deals with a family to which 

 the fictitious name of Nam has been attributed. 

 The origin of the Nams is described as follows : — 

 "In 1760 there lived in the mountains of Western 

 Massachusetts a set of people called Nam, 

 descended from the union of a roving Dutchman, 

 who had wandered there from the Hudson Valley, 

 and an Indian princess. These people were 

 wealthy in land, having inherited it from their 

 Indian ancestors." The family in more recent 

 times is said to be characterised by alcoholism 

 and lack of ambition. As in the case of the Hill 

 Folk, Dr. Davenport has prepared a bill of what 

 they have cost the State. We do not, however, 

 agree with his system of accounting, in which 

 everything is entered on the debit side and nothing 

 on the credit. Even the most valuable of citizens 

 would show up badly in this system. Thus the 

 largest item of the Nams' account, forming two- 

 thirds of the total, is their drink bill of rather 

 more than a million dollars, distributed among 

 700 of them. If we were to take 700 prosperous 

 professional men in England it would not be an 

 overestimate to suppose that each would have 

 a drink bill of something like 5000 dollars in fifty 

 years, or, combined, their total bill for drink would 

 be more than double the total bill of the Nams 

 for all items. Thus, if nothing is reckoned _ on 

 the credit side, we could come to the surprising 

 conclusion that the Nams were the less unprofit- 

 able of the two. 



