Febkuarv 1, 1895.] 



SCIENCE. 



121 



stant, and ojiens tlie terminal end of the 

 corresponding tube near the subject's nose. 



A pneumograph records the respiration. 

 The pulse, vaso-motor and respiratoiy 

 cun'es, the signal and time records (in 

 seconds) are all traced in ink on a horizontal 

 kymogi-aph. 

 Explanation of Xatiiral Immunity. George 



M. Sternberg. 



Dr. Sternberg, after a review of the experi- 

 mental evidence relating to the cause of the 

 natural immunity which exists among ani- 

 mals against parasitic invasion by various 

 pithogenic bacteria and by putrefactive 

 microorganisms, said that the experimental 

 evidence submitted, considered in connec- 

 tion with the extensive literature relating 

 to ' phagocA^tosis,' leads us to the conclusion 

 that natural immunity is due to a gennicidal 

 substance present in the blood serum, which 

 has its origin (chiefly at least) in the leuco- 

 cj-tes. and is solulile only in an alkaline 

 medium. And that local infection is usually 

 resisted by an afflux of leucocytes to the 

 point of invasion, but that phagocytosis is a 

 factor of secondary importance in resisting 

 parasitic invasion. 



AVarrex p. Lombard, 

 UxivERsiTV OF Michigan. Secretary fw 1894. 



AS ISUEREST ERROR IS THE VIEWS OFGAL- 

 TOS AND WEIS3IASS ON VARIATIOS.* 



Weismants's name has become so inti- 

 mately a.ssociated with the doctrine of germ- 

 inal continuity that he is often regarded as 

 its first advocate, although it is an old con- 

 ception which has found expression in many 

 writings. 



Among others I myself stated it in the 

 following words in a book printed in 188:5, 

 before the publication of Weismann's first 

 essay on inheritance. 



" The ovum, like other cells, is able to re- 

 produce its like, and it not only gives rise, 



• A paper read, by inNitatioii, at the meeting of the 

 Society of Xatntalists, in Baltimore, Dec. 27, 1894. 



during its development, to the divergent 

 cells of the organism, but also to other cells 

 like itself. The ovarian ova of the offspring 

 are these latter cells or their direct unmodi- 

 fied descendants." 



After the appearance of Weismann's es- 

 says, and the revival of discussion on the 

 views of Lamarck, I was much surprised 

 to find mj' book referred to as a Lamarckian 

 treatise, and my reason for quoting this pas- 

 sage now is not to claim prioritj-, but to 

 show that, in 1883, 1, like Weismann, attrib- 

 uted inlieritance to germinal continuity. 



I may take this occasion to say that I still 

 regard inheritance as a corollaiy or outward 

 expression of the continuity of living matter, 

 although I am less confident than I was in 

 1883 of the importance of the distinction 

 betn"een somatic and germinal cells. So 

 much for the doctrine of germinal con- 

 tinuity. 



Passing now to another topic, we find 

 that the two most prominent writers on in- 

 heritance, "Wiesmann and Galton, base their 

 views of variation on the assumption that, 

 at each remote generation, the ancestors of 

 a modern organism were innumerable, al- 

 though a little reflection will show that this 

 assumption is untenable. 



Weismann, at least in his earlier and sim- 

 pler writings, finds the cause of variation in 

 the recombination, by sexual reproduction, 

 of the effects of the diversified influences 

 which acted upon the innumerable protozoic 

 ancestors of each modei-n metazoon. 



If it can be proved that these protozoic 

 ancestors were not innumerable, but very, 

 very few, and that these few were the com- 

 mon ancestors of all the modern metazoa, 

 his position is clearly untenable. 



Galton's view of the cause of individual 

 diversity is very similar to Weismann's. 

 He says : " It is not possible that more than 

 one-half of the varietiett and number of tht- 

 parental elements, latent or personal, can 

 on the average subsist in the ofi'spriug. 



