FORMATION OF THE EMBRYO. 



307 



two embryos in the seed of the Mistletoe ; and there is usually a 

 plurality of embryos in Pines and other Gymnospermous plants 

 (560), though all but one 519 550 551 532 553 



are more commonly abor- 

 tive or rudimentary. There 

 arc other striking peculiar- 

 ities in the fecundation of 

 Tines, &c, which, however, 

 cannot be readily explained without 

 entering into more detail than is 

 here advisable.* In Tines and their 

 allies, moreover, the embryo is not 

 developed until a long time after the 

 application of the pollen, and the 

 fdling of the embryo-sac with the 



cellular tissue which forms the basis of the albumen of the seed ; 



the fruit and seed of 

 true Tines, as is well 

 known, not maturing un- 

 til the year after that 

 in which the blossoms 

 appear. 



580'. The further development and the structure of the embryo 

 and the seed* must be considered after the Fruit, of which it consti- 

 tutes a part. 



a 



* Sec Hofmcistcr, Untersucftungen, &c : Researches into the Fertilization, &c. 

 of the higher Cryptogamia and the Coniferaj (Lcipsie, 1851), with seven plates 

 devoted to the embryology of Coniferaj. 



FIG. 549 Dingram of the suspensor and forming embryo nt its extremity. 550 The same, 

 ■with the embrjo a little more developed. 551. The same, more developed still, the cotyledons 

 faintly indicated at the lower end. 552. Same, with the incipient cotyledons more manifest. 

 653. The embrjo nearly completed. 



FIG 554 - 556. Forming embryo from a half-grown seed of Buckwheat, in thrw jtages. 

 557. Same, with th« cotyledons fully developed. 



