4 1 6 MORPHOLOGY. 



History. 



We not (.infrequently find examples in Science, of the unprejudiced 

 glance of the first observer divining and expressing the truth, which, 

 however, is naturally at once thrown aside by Science as unfounded and 

 contradicting its temporary laws, till in the end it works back gradually 

 to that first notion, but now consciously, and supported in every way by 

 the true reasons. Thus, if we look to the result now secured as to the 

 origin of the embryo, it is at the bottom exactly the same as that which 

 was asserted more than a hundred years ago by Samuel Morland *, 

 namely, that the pollen-tube descended through the style into the seed-bud 

 and became the embryo. This notion, in its crude form, was contested, 

 and, indeed, at that time, properly, by Vaillant and Patrick Blair. After 

 that, all deeper investigation, such as had been roused by Malpighi, 

 gradually fell asleep ; and when Treviranus f wrote his work on the 

 Development of the Embryo, it was to be considered as a great advance, 

 although he did not go beyond what Malpighi had done, and even 

 did not reach many of the beautiful observations of Malpighi, e. g., 

 the existence of the embryo-sac. The observation of the embryo 

 in its earlier conditions, as the embryonal globule, from which Malpighi 

 and Treviranus started, commenced with Ad. Brongniart (7. c.), and 

 he very nearly completed the matter ; if he had only used the obser- 

 vations of Robert Brown, which soon followed, and by means of these 

 explained his observations on Momordica JElaterium, which only wanted 

 an intermediate stage, easily added hypothetically, he would have dis- 

 covered the origin of the embryo from the pollen tube penetrating into 

 the embryo-sac. Thus the materials stood till IJ brought the matter 

 to a conclusion by my researches. I regard it as wholly superfluous to 

 report on the many opinions of those whose imagination was busier in 

 spinning out their own discoveries, than their hands in dissecting or their 

 eyes in observing accurately people who in all ages have confused 

 natural science instead of advancing it. 



B. THE DEVELOPMENT OF THE EMBRYONAL GLOBULE INTO THE 

 EMBRYO. 



166. The main features of this section have necessarily been 

 already given ( 121.), but this is the place in which to enter into 

 this matter somewhat more specifically ; for this purpose it seems 

 requisite to separate the Monocotyledons from the Dicotyledons, 

 and the Gymnosperms from both. As an universal law, valid for 

 all Phanerogamia., there is only one thing to be expressed, that the 

 part of the embryonal globule corresponding to the point of the 

 pollen-tube always becomes the bud ; the opposite part therefore, of 

 course, that turned toward the apex of the embryo-sac, the nuclear 



Eapilla and rnicropyle, becomes the radicle. The existence of this 

 i\v of position of the radicle in the seed-bud was first stated by 

 Robert Brown. 



* New Observations on the Parts and Use of the Flower in Plants. Phil. Trans., 

 1703. 



f Von der Entwick. des Embryo, &c. Berlin, 1815. 



J Einige Blicke auf die Entwickl. des veg. Organismus, Wiegmann's Archiv, 18:37, 

 vol. i. p. 289. ; Ueber Bildung des Eichens und Entstehung des Embryo, Act. Acad. 

 C. L. C. vol. xix. p. 1. 



