

274 BOTANICAL GAZETTE [October 



entering the archegonium, one male nucleus in contact with the egg 



nucleus, and the second male nucleus, the stalk cell, and the tube nu- . 



cleus lying in the micropylar end of the egg. He also studied pollen 



tubes grown in five per cent, gelatin in sterilized pear juice. He noted 



the disorganization of the jacket cells and describes a fusion of the 



nuclei of the jacket cells with one another and their subsequent migra- I 



tion into the cytoplasm of the tgg. He also observed a large number 



of small nuclei in the egg, the nature and origin of which he was not 



able to determine. He further states that a suspensor ("prosuspen- 



seur" or ^^embryonalschlauch'') is not formed. ' The elongation of 



form 



columelle") is noted. 



embryogeny of E. trij 



is the continuation of the paper^ which dealt with spermatogenesis 

 and oogenesis in the same species. Material for the study was 

 collected at Mesilla, New Mexico, chiefly in April 1904. Much of 

 the material collected in 1903 was imfit for a study of fertilization 

 stages because of the ravages of a parasitic insect which attacked the 

 ovules about the time of pollination. Embryos having been observed 

 about April 20, 1903, it was hoped that by beginning to make collec- 

 tions as early as April i in the following season and continuing them 

 at intervals of two days a fairly complete series could be obtained. 

 Collecting was discontinued April 20, 1904, at which time the majority 



size. The season of 1904 



maximum 



md dry and in conseque] 

 much so in fact that em 



ma 



Not all of the material collected at the earliest date had been pollinated. 

 In iQoq staminate strobili sent from the Carnede Desert Laboratory, 



phyte. 



possible 



POLLEN TUBES AND lERTILIZATION 



Pollen grains were placed in a ten per cent, solution of saccharose 

 on a slide in a moist chamber. By evaporation the solution became 

 considerably denser toward the close of the experiment. Shordy 



w 



Box. 



Gazette 38:1-18. pis, i~j. 1904. 



I 



