436 Harris Hawthorne Wilder 



he points out that the correspondence, even in anatomical detail, is 

 often very great. "Also Beziehungen sind jetzt schon vorhanden; aber 

 wir wissen noch nicht, wie weit wir die Kette der Ursachen zuriick 

 verfolgen miissen, um das Tertium comparationis zwischen der spontan 

 entstandenen und der experimentell erzeugten Cyclopie zu finden." 



A recent paper of Stockard/* which is in bulk merely a matter of 

 nine pages, is one of the most remarkable of recent teratological papers, 

 as he obtains results similar to those of Spemann by a radically different 

 method. By treating the artificially fertilized eggs of the Teleost 

 Fundulus with a trace of magnesium chloride the author has been able 

 to produce, not once only, but again and again, cyclopean monsters that 

 pass all the standards of true Cosmobia. Individual specimens show 

 this peculiarity in different degrees, and the microscopic sections which 

 the author shows are as symmetrical and free from pathological sug- 

 gestion as are those of my incompletely dicephalous pig (Teras I) de- 

 scribed in the body of this work. 



These experiments are of the utmost importance in connection with the 

 present paper, and quite forbid me from taking the strong view concern- 

 ing a germinal variation as always the necessary cause which I might 

 otherwise have done. I am here very willing to say that Dr. Stockard's 

 Avork has been of the greatest value to me, and that this author has in 

 every way been extremely kind, both in writing me from time to time 

 concerning his experiments, and especially in placing in my hands the 

 first proof of a paper now in press, the results of which I am thus able 

 to take cognizance of as my last proof is leaving my hands. Lest, how- 

 ever, someone may be led astray as to Stockard's present views by read- 

 ing his early paper alone (1907) it may be permitted me to point 

 out here that his first assumption that the Cyclops monsters were 

 produced by a gradual approximation and subsequent fusion of two 

 lateral eyes was found by him to be incorrect, and that, in his newest 

 paper, he has corrected this, and now affirms, quite in accordance with 

 my position, that "the C3^clopian defect ... is present from the first 

 in the same condition that it will continue throughout development." 



Furthermore, if this claim of fusion l)e not true, and if such a process 

 does not take place during each individual development, it invalidates 



"Stockard, C. R. The influence of extern;il factors, chemic-nl and physical, 

 on the development of Fundulus heteroclitus. Journ. of Exper. Zool. Vol. IV, 

 No. 2, 1907. 



Stockard, C. R. Archiv fiir Entwick.-Mech., Vol. XXIII, 2 Heft, 1907. 



