502 



ON TRIPLE HYBRIDS. 



From the experiments described the following table may be 

 compiled: 



Triple hybrids and their succeeding generations. 



Quadruple hybrids. — The discovery of twin and triple hybrids 

 naturally suggests the idea of the possibility of a hybrid quartette. 

 As a matter of fact the experiments did the same. In the case of 

 0. lata X 0. biennis from Chicago a fourth type appeared in one 

 specimen, and in that of 0. lata x 0. Hookeri in two specimens. These 

 three plants belonged evidently to the lata type, but combined with 

 this the smooth, broad and bright-green leaves of the laeta, whereas 

 all the other latas of these crosses had gray and furrow-shaped leaves 

 like the velutina. The lata-laeta of the first cross was sufficiently 

 fertile, but of two of the Hookeri cross one had barren anthers and 

 the other only some spare pollen in comparison with the rich supply 

 of pollen in the other lata plants of this cross. In this respect, there- 

 fore, they also showed the character of the laeta type. 



It would seem probable that the lata-laeta should be produced in 

 the same number as the other lata, or lata-velutina as we could now 

 call it. But then the laeta itself often appears in too small numbers. 

 The cause of this phenomenon has still to be investigated. 



