56 



GRASSES OF IOWA. 



In wheat, according to Hays and Boss,* unusual variation 

 may occur. They state that the fife and blue stem pirents 

 only had very short awns, while in the 

 progeny there are several types with awns 

 of various lengths. Several of the plants 

 had dark-brown chaff, others chaff with a 

 light metallic tinge. Some of these varie- 

 ties may be due to previous crosses, and the 

 tendency of the plants to vary. The two 

 varieties crossed are not closely related, 

 one parent having hairy chaff and the other 

 smooth. 



Hybrids. 



Hybrids have been produced in grasses 

 oiySrtajuitaKlmens but they are rather difficult to work with, 

 andpistijs. (King.) owiug to the delicacy of the flower. 



The remarkable wheat and rye hybrids of Bliss Carman in 

 which fertile offspring took place in two distinct genera, 

 Triticum and Secale, are worthy of notice. 



Focket in his work on plant hybrids notes a number of 

 hybrid grasses. Thus he records a hybrid between the Avena 

 sativa and A. orientalis. There are also several hybrids between 

 species of the genera Poa and Calamagrostis and Alopecurus 

 and Bromus. He also records a hybrid between Aegilops and 

 Triticum. According to this it is stated that after several 

 years of culture a variety with constant characters is produced 

 which was called Aegilops b\6 by Pabre. It seems extremely 

 doubtful whether Pabre had a genuine hybrid in this instance. 



Wilson J seems to have produced a feriile hybrid between 

 Triticum and Secale, and they have even reported bigeneric 

 hybrids between Agropyron and Elymus. 



Immediate and secondary influence. — It is well known that in 

 some cases pollen has an immediate influence on the fruit or 

 seed. This has long been known to be the case in corn. As 

 long ago as 1758§ it was observed that when differently colored 

 varieties grew near each other they affected each other's seed. 

 Later experiments were made by Dr. Savi and Professor Hil- 



* Wheat: varieties, breeding, cultivation. Bull. Mlaa. A.gr. Exp. Sta. 63: 

 This valuable bulletin gives a great deal of vnluable Information on the subject. 

 + ])le Pflanzen mischllnge eln Beltrag zur Blologle der Gewachse. 407. 

 $ Trans. Bot Soc. Edlnb 12: 286. 

 § Darwin; Animals and plants under domestication, 1 : 430. 



460. 



