gJ4 NEW OEGAN TN SEEpS. 



understanding is convinced ; but i trust what lias beeii saiJ 

 will prove sufFici.cnt, to rcinuve the doubts of Opsimath. C. 



XIII. 



Memoir on the Organ hy tchich the fertUizlng Fluid is capa~ 

 ble of being introduced into the Ovula of Vegetables, By 

 P. Turpi N. Read at the National Institute, December 

 the Ath, 1808*. 



Discoveries ow- J[]S[ Natural HistovVj as in all oj;her sciences, v/e are some- 

 or^reasoTiing'^1- times indebted to chance for discoveries, though they more 

 e>-amination, frequently arise from the deductions of reasoning, and from 

 observation. It is to the last of these I owe the discovery 

 of the organ, which wi}l be described in this paper. This 

 organ, hitherto noticed only in the seeds of the leguminous 

 plants bj those celebrated bptanists Grew, Gleichen, and 

 Gcertner, and in our own days by Mirbel, according to my 

 researches forms a necessary part of the structure both of 

 ihonocotyledonous and dicotyledonous seedo. 

 Coats of a seed. Before we proceed let us examine what are the principal 

 organs, that the two coats of the ovula exhibit ; or, as the 

 readiest way, let us examine the proper coats of a seed ar- 

 rived at maturity. 

 Base of a seed It is admitted, that the base of the seed, whatever its 

 contains three ^pyj-g \^ always determined by the point which adheres to 

 different organs. => ' •' . . "•, • , , ' • j ■ 



the placenta. This pomt, which has received several names, 



such as umbilicus, hilum, and eye, comprises three distinct 

 organs, each having a different function to fulfil, yet all hi- 

 therto confounded by botanists under one term. 

 The hilum. The first of these organs, to which the name of hilum is 



perfectly adapted, is that cicatricula, which is most com- 

 monly called the umbilicus of the seed. The lips of this 

 cicatricula, which are sometimes very large, as in the sapota 

 plum, soap-berry, chesnut, and some legumes, inosculate 

 with the exterior vessels of the umbilical cord, which, divid- 



* Jiumal de Phy»iqii ■, vol. LXIII, p. 195. 



ing 



