6o TRANSACTIONS OF THE ILLINOIS 



Mr. Wiegman studied the cabbage, and speaks " with astonishment of the 

 vigor and height of the mongrels, which excited the amazement of all 

 the gardeners." "Mr. Chaundry raised a great number of mongrels by 

 planting together six distinct varieties of cabbage," which proved more 

 hardy than other cultivated sorts. Mr. Maund crossed varieties of wheat, 

 and found that the progeny had greater vigor. Mr. Knight's crossed 

 wheats were the only kinds that escaped the disastrous blights of 1795 

 and 1796, when almost the whole crop of England Avas affected. Mr. 

 Clotzsch crossed diHerent pines, oaks, alders, and elms, using distinct 

 species, and having sowed seeds of the originals and those of the hybrids; 

 the latter, diough losing in "fertility, often gain in size and constitutional 

 vigor." "All experimenters — Kolreuter, Gartner, Herbert, Sageret, 

 Leecog, and Naudin — have been struck with the wonderful vigor, height, 

 size, tenacity of life, precocity, and hardiness of their hybrid productions. 

 * * * Some exceptions have been observed by Gartner and Herbert; 

 but the most striking of these are given by Max Wichura, who found 

 that hybrid willows were generally tender in constitution, dwarf, and 

 short-lived." 



Causes of Variation. — There are many puzzling questions in the 

 study of Horticulture, some of which refuse to yield a solution to any 

 thing short of a magician's wand. Look at our extended lists of fruits; 

 examine the products, observe their varying shapes, colors, flavors, and 

 qualities, as we gather them from our orchards, from our vines, and from 

 our berry plantations, and who can say why the Almighty has framed 

 them so wonderfully, and made them so to difl^er from one another for 

 our use and enjoyment.'' 



It has been assumed that these variations are due to the changed 

 conditions of the plants of culture, which are often very different from 

 those which are natural to the plants. Many of our farm crops, especially 

 the grains, have been so long cultivated by man that their origin has been 

 lost sigiit of; hence we do not now know the original type with any 

 certainty. In these, it is easy to say that their tendency to vary is owing 

 to loftg' conti}iucd citltivatiofi. 



We may safely infer that the peculiar conditions surrounding our 

 plants should have exerted an influence in modifying their forms and 

 characters; hence, some writers have referred variation to high culture^ 

 on one hand, or to starvation and sterility of the soil, on the other. 

 Excess of food might tend to extraordinary development, while starvation 

 would naturally incline to leanness, or weakness and diminished vigor, in 

 plants as well as animals. 



Climate has been supposed to exert a very great influence in modify- 

 ing the forms and characters of plants, and here we find that very narrow 

 limits are allowed to some plants, while a wider range is possible to 

 others. Each of our fruits seems to require a given amount of tem- 

 perature between its blossoming and its ripening. This period may, 

 however, be extended or curtailed for the same variety in different 

 climates, but still within quite narrow limits of extremes and of mean 

 temperature, and so we have ranges of latitude that are appropriate to 



