966 Transactions of the American Institute. 



April 9, 1868. 

 Prof. S.D. Tillman in the chair. 



The Chairman opened the meeting with the following: 



PURE HYBRIDIZATION. 



J. Anderson Henry, Esq., in a paper read at the Botanical Society 

 of Edinburgh, on crossing distinct species of plants, stated the 

 rules and means used by him to insure success, the purport of 

 which is contained in the following: 



1. It is of vital importance to have the separate plants intended 

 for the parents in the cross, even though both were hardy, brought 

 under glass, in order to heighten the temperature and protect the 

 plants against wind and insects. In the height of summer, how- 

 ever, pollen may be taken from an outside phmt to cross with an 

 inside one, and vice versa. 



2. It is not enough merely to emasculate the seed-bearing flower. 

 Every petal should be taken oif, for it attracts insects, which seem 

 to be guided more by their optics than any sense of smell. Emas- 

 culation should be performed long before the expansion of the 

 bloom, because, in many plants, fertilization often takes place in 

 the unopened flower. In some cases a gauze bag should be put 

 over it, to protect the mutilated bloom from the most troublesome 

 of insects, the bumble-bee, which, in his unwieldy flight, may come 

 across it by pure accident. 



3. Do not be in a hurry to effect a cross; wait till the stigma is 

 found to be fully developed. This is indicated in many plants by 

 a glutinous exudation on the summit, in others by the feathery 

 expansion, and recurvature of its separate divisions. 



4. Next obtain properly ripened pollen grains from the male 

 plant. This is done by carefully watching when the anthers burst 

 open, otherwise the insects may be before you. So active are they 

 on such favorite food as the pollen of the rebus tribe' (which 

 includes the blackberry and raspberry), that it may be found neces- 

 sary to incas.e the opening bloom in muslin bags. Do not use, as 

 is generally recommended, the camel-hair pencil, for if applied 

 often and indiscriminately, it may convey with the foreign, some 

 insidious grains of native pollen, which, however few, are pre-potent, 

 and wholly neutralize the former. Take, where it can be obtained 

 and afibrded, the entire bloom of the intended male, and give the 

 slightest brush with all its anthers over one or all of the stigmas 

 of the intended female. Both long and short anthers may be used, 



