HYBRIDISING AND CROSS-BREEDING. 105 



when boiled, while the other remained hard. But these are 

 only observations, and not experimental results. Wiegmann 

 first obtained the latter in Peas. Gaertner tested experiment- 

 ally many of the statements which we have quoted, and made 

 experiments on other plants besides. He was only able, how- 

 ever, to confirm Wiegmann's results to a certain extent. He 

 is therefore disposed (and with much reason) to attribute the 

 majority of such cases to variation in the individual ; he allows, 

 however, as a rare exception, the possibility of change even in 

 the mother plant itself. Other observers (as, for example, 

 Knight,* and recently even Nageli t) deny even the possibility 

 of such an influence. 



" More recently Darwin has again quoted cases J where, by 

 crossing yellow and dark Maize, cobs were produced which 

 contained both yellow and dark grains. Hildebrand confirms 

 these observations, and further cites the instance of an Apple 

 which bore traces in its marking of the influence of another 

 sort But whilst the question has been in these cases only a 

 variation in the colour, in the three which follow we find it 

 affecting the form. Hartsen|| has seen on Solatium edule (the 

 well known Egg plant) a fruit which in colour, size, and shape 

 exactly resembled a Tomato, and possessed only the greater 

 dryness and firmness of the flesh of the Egg fruit, besides the 

 smooth border of the seed, which in the Tomato is villous. 

 Dr Kanitz IT met with a case of a hybrid fruit, between Lycoper- 

 sicum esculentum and Capsicum annuum. Fritz Miiller** fertilised 

 Cattleya Leopoldi by Epidendrum cinnabarinum, and obtained 

 seeds of the former with the shape belonging to the latter. 

 Meehan,tt lastly, observed that the bough of a Pear-tree, which 

 had always been altogether unfruitful, projected into the boughs 

 of a neighbouring Apple-tree. Fruits were produced, which in 

 skin, flesh, and other respects were altogether Apples, and had 

 only the seeds, carpellary partitions, and stalk of the Pear. 



" These are all the cases with which I am acquainted. Con- 

 sidering, then, that the observations of Bradley, which are the 

 earliest, date from the year 1721, and that the list has only 

 increased very slowly, notwithstanding the vast opportunities for 

 noticing these cases which botanists and gardeners have had in 

 crossing different species of plants, we must allow that Gaert- 



* Trans. Royal Hort. Soc., v, 67. 



t Sitzungsberichte d. bayerischen Akad., cited by Hildebrand. 

 Savi, cited by Darwin, /. c. p. 400. 



Bot. Zeit, 1868, p. 325, t. 6. || Bot. Zeit., 1867, p. 378. 



IT Bot. Zeit, 1867, p. 335. ** Bot. Zeit., 1868, p. 631. 



ttProc. Acad. Nat. Sc. Phil, 1871, vol. i. 



