408 



SCIENCE 



[N. S. Vol. XLIII. No. 1108 



Their (the systematists ' ) business is purely 

 that of the cataloguer, and beyond that they can 

 not go. 6 



After full and calm reflection it seems to 

 me that it is not too much to say that this 

 utterance is proof positive that its author 

 is hardly competent to pass an opinion on 

 the work of his colleagues in other fields of 

 biology however great his achievements in 

 his own province. Castle expresses the 

 following opinion : 



It is easy to dispose of the work of the syste- 

 matist by assuming that he does not know his 

 business, but is it wise to do so? ^ 



As a matter of fact it seems to me that 

 the systematist is affected not at all by Men- 

 delianism. His species must be limited on 

 phenotypic grounds alone, because the ex- 

 ternal appearance and morphology are all 

 that can possibly be known of all but an 

 infinitesimal fraction of the hundreds of 

 thousands of species that must be dealt 

 with. He cares little about what is done 

 with domesticated animals, nor is he 

 greatly interested in forms produced under 

 abnormal conditions of captivity, cross fer- 

 tilization or other forms of enforced biolog- 

 ical immoralities. Of the 10,000 species of 

 modern birds, for instance, how many can 

 be established on factorial grounds 1 When 

 it comes to the half million or so of insects, 

 a few score, or perhaps hundreds of species 

 might be worked out in the laboratory by 

 Mendelian rules ; but the laboratory condi- 

 tions are usually highly unnatural, and it 

 is safe to say that the results would be end- 

 less contradictions and confusion worse 

 confounded; and the remaining hundreds 

 of thousands of species would still have to 

 be dealt with phenotypically or not at all. 



So, too, with the innumerable marine 

 forms of invertebrates, a single order of 

 which is a man's job for a life-time, if he is 

 to distinguish them phenotypically alone. 



6 Science, August 14, 1914, p. 245. 



7 Science, XLl., p. 98. 



The task is absolutely hopeless if treated 

 genotypically. 



The systematist knows that species differ 

 from each other in very numerous small 

 characters, and that, even if they would 

 lend themselves to factorial analysis, the 

 result would be much more perplexing than 

 the present system which continually 

 evokes the wrath of our nonsystematic col- 

 leagues. 



Nor will our work be exclusively, or even 

 mainly, that of the cataloguer. With the 

 aid of our friends the morphologists, em- 

 bryologists and paleontologists we will con- 

 tinue to unravel the tangled skein of de- 

 scent; and our opinion will be valued in 

 proportion to the honesty, patience and 

 skill which we bring to our work, just as it 

 always has been. 



And so, I think, we can rest easy in 

 the continuance of our job. Meanwhile we 

 can greatly admire the man who busies 

 himself with the microcosm of the cell, 

 and bid him God-speed. We can contem- 

 plate with sympathetic delight the experi- 

 mental zoologist as he shakes the eggs of 

 the sea urchin and salts them with various 

 kinds of salt. 



We can even derive pleasure and much 

 entertainment from the marvelous feats of 

 our ultra-Mendelian friend, in full assur- 

 ance that he will produce a factor that will 

 meet every possible requirement; and that 

 if he doesn't produce the factor he will 

 have an inhibitor at hand to explain why 

 the thing doesn't work. And we can rest 

 calm in the faith that, if neither factor nor 

 inhibitor is forthcoming, he will in no wise 

 be abashed, but will calmly declare the 

 form under scrutiny to be nothing but a 

 fluctuating variety, and will smilingly cast 

 it into the discard along with the systema- 

 tist, who will just as smilingly proceed 

 with his customary activities. 



C. C. Nutting 

 State University of Iowa 



