FERTILIZATION IN ABIES BALSAMEA 



CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 210 



A. H. Hutchinson 



(with plates xvi-xx and one figure) 

 A general account of fertilization and the related phenomena 

 in this species has been given by Miyaki (19) . A number of super- 

 numerary nuclei were noted in the micropylar end of the egg at 

 the time of fertilization. These were generally regarded as derived 

 from the male gametophyte, while in some cases another nucleus, 

 that of the ventral canal cell, was added to the number. Repeti- 

 tion has been avoided, inasmuch as the present account is restricted 

 to special problems, while the general account has received little 

 attention. 



The problems suggested by the regular occurrence of four nuclei 

 in the egg cytoplasm, near the micropylar end, at the time of the 

 4-nucleate proembryo, and by the unusual grouping of chromosomes 

 during the division which follows the conjugation of the egg and 

 sperm nuclei, have led to this investigation. Special attention, 

 therefore, will be given to the fertilization of the nucleus of the 

 ventral canal cell and to the cytological features connected with 

 the fertilization of the egg. 



The material was collected in Ontario, Canada. I am greatly 

 indebted to Professor W. R. Smith for collections made at Lake 

 Joseph. On June 25 and 26 I obtained ovules showing fertilization 

 at N. lat. 44 , W. long. 79°i2', and on July 2 and 3 ovules showing 

 similar stages at N. lat. 45°3o\ W. long. 78°32'. The altitude in 

 the first case was 900 feet; in the second 1800 feet. 



In a former paper on the male gametophyte of Abies (10), the 

 excessive number of prothallial cells has been recorded. One of 

 these polar cells, during mitosis, is shown in fig. 1. Fig. 5, which 

 was drawn from a pollen grain lodged in the micropyle, shows the 

 division of the body cell nucleus, to form two male nuclei, taking 

 place before the tube breaks through the spore coat. At this tune 

 the cytoplasm surrounding the tube nucleus is extremely vacuolate, 

 457] [Botanical Gazette, vol. 60 



