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POPULAR SCIENCE MONTHLY. 



tention could the stream effects be 

 disting-uished. I am certain, however, 

 that they were there and that the 

 direction was upwards towards this 

 anti-helial (?) position everywhere. 



The appearances noted, were highly 

 suggestive of luminous matter of some 

 sort streaming past the earth on all 

 sides with tremendous velocity in a 

 direction away from the sun — the 

 parallel streams being rendered ap- 

 parently convergent by perspective. 



The aurora, however, is believed to 

 be a strictly terrestrial phenomenon 

 in the nature of an electrical discharge 

 in the higher regions of the atmos- 

 phere; although good grounds exist 

 for supposing that there is some inti- 

 mate connection between great auroral 

 displays on the earth and disturbances 

 going on in the sun. 



In this connection it would be inter- 

 esting to know where Borelli's comet 

 was at the time. It was then rapidly 

 nearing its closest approach to the 

 sun. 



Alexander Graham Bell. 

 Beinn Bhreagh, near Baddeck, Nova 



Scotia, September 26, 1903. 



MR. COOK ON EVOLUTION, CYTOL- 

 OGY, AND MENDEL'S LAWS. 

 To THE Editor: Owing to my ab- 

 sence in Europe, Mr. 0. F. Cook's 

 article, published under "the above 

 ti'tle in the July number of the Pop- 

 ular Science Monthly, has only now 

 come to my attention. Mr. Cook's 

 somewhat drastic criticism of the sue- 

 gestion regarding Mendelian inherit- 

 ance, made in my article in the issue 

 of Science for December 19, 1902, 

 takes a prominent place in his essay 

 and relates to a question of wide bio- 

 logical interest. I, therefore, ask 

 space to point out that he failed to 

 grasp the nature of the suggestion; and 

 unfortunately the confusion was worse 

 confounded by his misquotation, of 

 course unintentional, of my own state- 

 ment in such a way as to make me 

 seem to commit the very erroi- that is 

 the object of his criticism, though I 



myself had expressly warned against 

 such an error in a paper read before 

 the Washington meeting of the Ameri- 

 can Association last December! 



Mr. Cook's objection to the sugges- 

 tion, as he understood it and as he 

 quoted it, is perfectly correct, and the 

 man of straw thus set up by his own 

 hand is properly overthrown. As- 

 suredly, to maintain that the reducing 

 division in the maturation of the germ- 

 cells ' leads to the separation of 

 paternal and maternal elements and 

 their ultimate isolation ' as ' separate 

 germ-cells' (this as quoted by Mr. 

 Cook, italics mine) involves, as he 

 points out, the reductio ad absurdum 

 that the individual could not show 

 characters individually traceable to 

 more than two grandparents; for this 

 form of statement implies that purely 

 paternal or maternal groups of chro- 

 mosomes are separated by the division, 

 to be isolated as such in the gametes, 

 tlie latter being thus rendered pure 

 in respect to parentage. But this, of 

 course, was not my meaning, nor was 

 it what I said. Mr. Cook failed to 

 perceive that my statement referred, 

 not to the parental groups, but to the 

 members of the individual pairs of 

 paternal and maternal chromosomes. 

 What I said was the isolation of the 

 paternal and maternal elements, not 

 ' as ' but ' in ' separate germ-cells ; and 

 the elements thus separated from each 

 other were specifically designated as 

 ' the members of each pair.' I regret 

 that Mr. Cook did not read with greater 

 attention; for my phraseology was 

 carefully chosen, the untenability of the 

 view which is erroneously ascribed to 

 me having been clearly pointed out by 

 Mr. Sutton when he first brouo-ht 

 his suggestion to my attention, and 

 since fully considered by him in an 

 article on 'The Chromosomes in 

 Heredity' published in the Biological 

 Bulletin for last April. It is only 

 fair to add that since Mr. Cook ac- 

 cuses me, as he does Mr. Cannon, of a 

 failure to understand the Mendelian 



