442 OBSERVATIONS ON THE STRUCTURE 



ceed to state the various observations that have been ac- 

 tually made, and the opinions that have been formed on the 

 subject as briefly as I am able, taking them in chronological 

 order. 



In 1672, Grevp^ describes in the outer coat of the seeds 

 of many Leguminous plants a small foramen, placed oppo- 

 site to the radicle of the Embryo, which, he adds, is " not a 

 hole casually made, or by the breaking off of the stalk," 

 but formed for purposes afterwards stated to be the aera- 

 tion of the Embryo, and facilitating the passage of its radicle 

 in germination. It appears that he did not consider this 

 foramen in the testa as always present, the functions which 

 lie ascribes to it being performed in cases where it is not 

 found, either, according to him, by the hikim itself, or in 

 hard fruits, by an aperture in the stone or shell. 

 642] 111 another part of his work^ he describes and figures, 

 in the early state of the Ovulum, two coats, of which the 

 outer is the testa ; the other, his " middle membrane," is 

 evidently what I have termed nucleus, whose origin in the 

 Ovulum of the Apricot he has distinctly represented and 

 described. 



Malpighi, in 1675,^ gives the same account of the early 

 state of the Ovulum ; his " secundinse externse " being the 

 testa, and his chorion the nucleus. He has not, however, 

 distinguished, though he appears to have seen, the foramen 

 of Grew, from the fenestra and fenestella, and these, to 

 which he assigns the same functions, are merely his terms 

 for the hdimi. 



In 1G94, Camerarius, in his admirable essay on the 

 sexes of plants ,* proposes, as queries merely, various modes 

 in which either the entire grains of pollen, or their particles 

 after bursting may be supposed to reach and act upon the 

 unimpregnated Ovuhi, which he had himself carefully ob- 

 served. With his usual candour, however, he acknowledges 

 his obligation on this subject to Malpighi, to whose more 

 detailed account of them he refers. 



' Aimlomii of Veget. beffim p. 3. Aiiat. of Plants, p. 2. 



- Jiiat. qfPlarUs, p. 2L0, lab. 80. -^ Aiiatome Plant, p. 75, et 80. 



' liiid'dphi Jucobi Camera rii de sej'u planturum epistola, p. 8. 40, et scq. 



