FATE OF SECOND MALE NUCLEUS IN EMBRYO-SAC. 177 



resting condition, can scarcely be distinguished from the nucleus of 

 an unfecundated egg. The nucleoli finally unite also. 



The worm-like or S-shape form of the male nucleus in Lilium, 

 first described by the author in 1897 (Mottier, '97, p. 23), has since 

 that time attracted the close attention of students of fecundation 

 generally. Guignard, having observed the same phenomenon in 1899, 

 concluded to designate these vermiform nuclei as antherozoids, evidently 

 attributing to them the power of locomotion. As a matter of fact these 

 nuclei do not possess cilia or any other cytoplasmic organ of loco- 

 motion, nor have the male nuclei in any Angiosperm been found to 

 possess any such structures. Nuclei in many vegetative cells of both 

 plants and animals are known to be able to change their form, and the 

 fact that in the embryo-sac the male nuclei may assume a worm-like 

 shape, which merely suggests a squirming or vermiform motion, is not 

 a sufficient reason for designating them as spermatozoids. So far as 

 is known, all spermatozoids are provided with a cytoplasmic organ of 

 locomotion, existing in the form of a cilium or cilia, and it certainly 

 does not conduce to clearness to apply this term to the male nuclei of the 

 Angiosperms. Strasburger (1900) claims that the vermiform nucleus 

 moves passively in the embryo-sac, basing his opinion upon observa- 

 tions of the embryo-sac of Monotropa in the living condition. A 

 streaming movement was seen in the cytoplasmic strand connecting 

 the egg-cell with the endosperm nucleus, and, in the light of this fact, 

 it is highly probable that the second male nucleus is carried to <the 

 endosperm nucleus by that means. 



THE FATE OF THE SECOND MALE NUCLEUS IN THE 



EMBRYO-SAC. 



The fact that one of the male nuclei fuses with a polar nucleus, or 

 with the endosperm nucleus in certain lilies and in species of widely 

 separated families, has also aroused a keen interest among botanists, 

 and has called forth much interesting and suggestive speculation. In 

 1897 the author called attention to the fact that the second male nucleus 

 in Lilium martagon applied itself to one of the polar nuclei, but the 

 . actual fusion was not observed. The plants from which the material 

 was obtained produced few or no seeds that year, and all preparations 

 of embryo-sacs, examined at a time when normally fecundated eggs 

 should have been present, gave only evidence of disorganization, and 

 it was concluded that probably a fusion of the nuclei did not proceed 

 further, which under the circumstances may have been true. Later, 

 other investigators as well as the author have observed this nuclear 



