328 ENVIEONMENT AMONG ANIMALS AND PLANTS 



a compact flower. On the other hand, seeds gathered from such 

 plants growing at a high altitude and sown in the neighbourhood 

 of Paris produced after three years elongated stems with less 

 hairy and brighter leaves, or, in other words, plants very similar 

 to those grown from seeds obtained in the neighbourhood of 

 Paris. The modifications acquired during a given time by 

 a lowland plant grown at a high altitude, or by a highland plant 

 grown at a low altitude, took about the same time to disappear 

 on returning the plants to their original climates.^ Similarly 

 ' Schubeler sowed seeds of various plants in different latitudes 

 in Norway and proved that the brilhancy of the flowers increased 

 with the latitude. So great was the difference that it was difficult 

 to conceive that they were produced from the same batch of 

 seeds.' 2 Observations on European peach-trees transported to 

 Reunion were made by Bordage. Such trees lost their deciduous 

 habit and became evergreen, though in some cases it took twenty 

 years before the change was complete.^ Lastly the red primrose 

 ' reared at a temperature of 30°-35'' C. (with moisture and shade) 

 has pure white flowers, but the same plants reared at 15°-20° C. 

 have red flowers. If the white-bearing plants are brought into 

 a cooler place, the flowers that are already in bloom remain 

 white, but those that develop later in the cooler temperature 

 are red.' * 



We may also notice the results of some of the experiments 

 upon developing animals. Stockard experimented with the fish 

 Fundulus heteroclitus. He subjected the eggs both before cleavage 

 began, and after the two- and four-celled stages had been reached, 

 to solutions of magnesium salts in sea-water. The eyes of a large 

 percentage of the embryos were abnormal. In some cases there 

 was a single median eye ; in other cases there was a median eye 

 showing signs of a double structure.^ ' In a long series of experi- 

 ments Fere has shown that monstrosities can be produced by 

 exposing the hen's egg to the unfavourable influence of a large 

 variety of substances. Vapour of ether, alcohol, essential oils, 

 nicotine, mercury and phosphorus, injection of alkaloids such 

 as morphine, nicotine, strychnine and others, of bacterial toxins 

 (those of tubercle and diphtheria), of peptone, dextrose, and 



' Vemon, Variation in Animals and Plants, p. 312. 2 Quoted from Henslow 



by Vemon, ibid. 3 Thomson, Animal Life, p. 407. ^ Morgan, 



Mechanism of Mendelian Heredity, p. 38. » Stockard, Journal of Experimental 



Zoology, vol. vi, p. 334. 



