On Nuclei in the Fertilised Embryo-sac of Lilium Martagon. 163 



" On the Presence of two Vermiform Nuclei in the Fertilised 

 Embryo-sac of Lilium Martagon" By Ethel Saegant. Com- 

 municated by Dr. D. H. Scott, F.B.S. Beceived April 28, — 

 Eead May 4, 1899. 



In a communication to the Russian Scientific Congress, which met 

 at Kieff, last summer, Professor S. Nawaschin summarised the brilliant 

 results of his recent work on the fertilised embryo-sac of Lilium Mar- 

 tagon and Fritillaria tenella (August 30, 1898). The report of this 

 paper, published in the 'Botanisches Centralblatt ' for January 4, 1899, 

 led Professor Leon Guignard to contribute a short account of his hitherto 

 unpublished researches on similar stages in the life-history of some 

 species of Lilium (L. martagon, L. pyrenaicum, and others) to the Aca- 

 demie des Sciences of Paris (April 4, 1899). 



The results thus obtained independently by two distinguished 

 botanists are in perfect accord, and present the greatest theoretical 

 interest. They find that both the male generative nuclei on emerging 

 from the pollen tube are elongated in shape, and that each is more or 

 less twisted on its own axis. The nuclei, in fact, appear to have been 

 killed by the fixative in the act of spontaneous movement within the 

 embryo-sac. M. Guignard compares this motion to that of a non- 

 ciliated antherozoid.* The " vermiform " shape can be traced in the 

 male nucleus for some time after it has joined the nucleus of the 

 ovum.f 



The most startling discovery, however, is that the second generative 

 nucleus unites with the upper polar nucleus of the embryo-sac, and 

 that both then fuse with the lower polar nucleus. Thus the definitive 

 nucleus of the embryo-sac, which later on gives rise by repeated divi- 

 sion to the endosperm nuclei, is formed by the coalescence of three 

 nuclei of very different origin. One is the sister-nucleus of the male 

 element in the fertilised ovum ; another, the sister-nucleus of the 

 female element ; and the third has all the characters of a vegetative 

 nucleus. Professors Nawaschin and Guignard are in complete agree- 

 ment as to these facts. M. Guignard adds that occasionally the polar 

 nuclei have united before the arrival of the " antherozoid," and gives 

 a number of figures in which the triple fusion is perfectly clear. 



I am fortunate enough to possess a few preparations from the fer- 

 tilised embryo-sac of Lilium Martagon, which, so far as they go, com- 

 pletely confirm the results of Professors Nawaschin and Guignard. 

 The material was fixed in absolute alcohol for researches which were 

 never even begun, but I cut a few hand sections from it immediately 



* Guignard, ' Comptes Rendus,' April 4, 1899, p. 3 of the separate copy, 

 f Guignard, loc. cit., p. 6 and figs. 3 — 5, 7 — 11. 



