142 



SCIENCE. 



[N. S. Vol. XXIII. No. 578. 



oxide. The tellurium was purified from the 

 members of the other groups of the Men- 

 delejeff's table by precipitating the chloride 

 with sodium thiosulphate, and treating the 

 Na.S.TeO, formed with an alkali. The Te 

 thus obtained was further separated from 

 members of the same group by fractional sub- 

 limation of TeO„. The results obtained for 

 the atomic weight of tellurium agreed very 

 closely with that previously obtained by 

 Brauner, Kothner and others, and the con- 

 clusions were drawn that the atomic weight 

 of Te has been accurately determined, that the 

 Te used contains no other element known or 

 unknown, and also that the atomic weight of 

 iodine has been correctly determined. The 

 position of Te in the sixth or eighth group 

 of the table was also discussed. 



Arthur M. Comey, 



Secretary. 



DISCUSSION AND CORRESPONDENCE. 



HEREDITY AND SUBSPECIES. 



I HAVE read with deep interest, and some 

 surprise, two recent articles in this journal 

 ^ by President David Starr Jordan, entitled, re- 

 spectively, ' The Loch Leven Trout ' ' and 

 ' Ontogenetic Species and Other Species.' " To 

 take them up in sequence, the facts presented 

 in the first article are, in substance, that a 

 trout found in Loch Leven differs from the 

 trout of neighboring lakes and streams in its 

 ' large size, more silvery color, sparcity of 

 spots, the red spots and ocelli characteristic 

 of the brook trout ^ * * * being usually 

 wanting,' while ' the orange edge of the adi- 

 pose fin, characteristic of the brook trout, is 

 wanting in the Loch Leven trout.' These dif- 

 ferences are so marked that the Loch Leven 

 trout (Salmo levinensis) ' has been usually 

 considered as a valid species, distinct from 

 the other trout of Great Britain.' President 

 Jordan cites Dr. Day as stating that the Loch 

 Leven trout changes into the ordinary brook 

 trout of England (Salmo fario), 'when 

 planted in streams of Gloucester or Guilford, 

 the colors of the Loch Leven trout being seen 



' Science, N. S., Vol. XXTI., No. 570, pp. 714, 

 715, December 1, 1905. 



^^ /6id., No.; 574, pp. 872, 873, December 29, 1905. 



on exceptionally well-fed individuals only.' He 

 also quotes Dr. Day as regarding some fifteen 

 or more other commonly recognized species of 

 trout inhabiting the lakes, streams and 

 estuaries of Great Britain and northern 

 Europe as ' all forms of one and the same 

 species ' ; and adds : 



A member of one of these so-called species would 

 be changed to one of the others if it grew up 

 under the same surroundings. These forms are 

 not subspecies, for that implies a divergence which 

 sliould be hereditary, however slight. They are, 

 if this view is correct, local variations of one 

 species, * * *. 



Elsewhere in the same article. President Jor- 

 dan states the results of transferring Loch 

 Leven trout to the waters of the Yosemite 

 National Park in California, where in the 

 course of ten years they have come to be ' ex- 

 act representatives in form and color of the 

 common brook trout as seen in the streams 

 of England.' He further says : ' These Loch 

 Leven trout in the Yosemite are typical 

 Salmo fario, or brown trout of England.' 



While these facts are of extreme interest, 

 and have an important bearing on the evolu- 

 tion and character of local forms, they merely 

 emphasize and confirm conclusions derived 

 from general considerations, and not based on 

 experimental research; or, as in this case, on 

 the incidental results of fish-culture. They 

 point the way, however, to a field of investiga- 

 tion evidently pregnant with interesting re- 

 sults, to which President Jordan has forcibly 

 called attention in his later article on ' Onto- 

 genetic Species and Other Species.' In this 

 paper, however, he takes a position that seems 

 to me quite new, and directly antagonistic to 

 the views held, I think, by the generality of 

 students of geographical variation in birds and 

 mammals, as regards the nature of species and 

 subspecies. He says, for example: 



It remains, however, to be determined whether 

 these environmental forms — these species and sub- 

 species produced by the direct influence of heat, 

 cold, humidity and aridity — are ' ontogenetic 

 species ' * * * or whether they have a real ex- 

 istence outside tlie lifetime of the individuals 

 actually composing the group or species. We 

 do not l^now wliich of the traits induced tiy 

 direct action of the environment, if any, are 



