Tower's experiments with Colorado potato beetles 

 seem to show that environmental influences may affect the 

 germ plasm to such an extent that the progeny will show 

 permanent variations. He subjected some of the beetles 

 to changed conditions of heat and cold and moisture, when 

 the reproductive organs were at a certain stage of develop- 

 ment. The progeny were decidedly paler than their par- 

 rents, but were fully as healthy. Moreover, these pale beet- 

 ties when mated produced offspring like themselves, and so 

 on for subsequent generations. 



Some recent experiments with alcoholized guinea-pigs 

 reveal the fact that the germ plasm is aflfected, for the 

 majority of the offspring of such guinea-pigs are defective in 

 many particulars.^ 



(b)— Telegony 



Telegony is the supposed influence of a previous sire on 

 offspring subsequently borne by the same female to a dif- 

 ferent sire. There is a widespread belief in Telegony, and 

 many examples can be cited in its support. The case of 

 Lord Morton's mare, cited by Darwin, is a classic example 

 {Animals and Plants Under Domestication, and Thomson, 

 Heredity). A nearly pure-bred Arabian chestnut mare 

 bore a hybrid to a quagga stallion. Subsequently she bore 

 two colts, a female and a male, to a black Arabian stallion 

 These colts were dun-colored and were striped on the legs, 

 one having in addition stripes on the body and neck. They 

 had also quagga manes, the hair being short, stiff and up- 

 right. Lately, Prof. Ewart, by repeating the experiment, 

 (the Penycuick Experiment) has shown that there is no 

 proof of any influence of a previous impregnation. 



Prof. Ewart points out that several marks of the an- 

 cestral forest type, such as the yellow dun color, the dorsal 

 band, the zebra-like bars on the legs and often the faint 

 stripes on the face, neck and withers, are quite common 

 among Arabian crosses. 



In Lord Morton's crosses "the bars on the legs were 

 more marked on the hybrid, on the filly, and on the colt 

 than on the quagga." 



More recent experiments by Baron de Parana and the 

 U.S. Government (Rommel) confirm Prof. Ewart 's con- 

 clusions as to the untenability of the theory of telegony. 

 (Read Chapter 36, Genetics in Relation to Agriculture by 

 Babcock and Clausen). 



(1) — Are Somatic variations ever inherited according to Mendelism? 

 (See Emerson, Amer. Nat. 48, 1914). 



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