250 PHILOSOPHIC^, TRANSACTIONS. [anNO IjGd. 



cles; they are usually shaped like a thorn, or prickle, widening towards the 

 base. They are each of them furnished with a canal, or tube, which divides 

 itself at the broader part of the hair, and enters the pistillum in two branches 

 (fig. 17) which run on till they join the longitudinal ducts that lead to the ger- 

 men (fig. 21.) These canals, after they enter the pistillum, are less regular, 

 branching out frequently into smaller ones, which, instead of running directly 

 to the longitudinal ducts, vary their direction, and fall into the canals that run 

 from the hairs next adjoining, furnishing the appearance of an irregular reticu- 

 lation (fig. 22,) though nevertheless there are commonly principal canals ob- 

 servable that run more directly towards the longitudinal ducts, and fall into 

 them (fig. 22.) The corpuscles are admitted into the hairs in the following 

 manner; the grains of the pollen having dispersed themselves about the style 

 and stigma, great numbers of them find a lodgement among the hairs; those 

 which fall between the hairs, or cling to their sides, may be supposed to lose 

 their effect; which will not be thought improbable, if it be considered what an 

 abundant provision there is of the pollen, and how large a part of it must neces- 

 sarily be wasted by being carried away by the flower, or at least not falling on 

 the female organs, but there are many of the grains that fall on the points of 

 the hairs (fig. 23,) and these furnish the impregnation. The grains being ar- 

 rived at a state of maturity before they issued from the antherae, are prepared to 

 burst and discharge their contents when they fall on the hairs, and the female 

 organ assists likewise in producing this effect; for soon after a grain has lodged 

 itself, the point of the hair begins to open, and the mouth extends itself by de- 

 grees over the surface of the grain, till almost the whole body of the grain is 

 drawn within the tube (fig. 23 ;) in this situation, the grain soon yields to the 

 compression of the tube, and discharges its corpuscles, which, with the assist- 

 ance of the fluid parts of the pulp that enter with them, or of the juices with 

 which the tube itself is furnished, float on till they enter the longitudinal ducts 

 which convey them to the germen. The grains, after thus emptying themselves 

 of their contents, wither and contract, and, falling oft' from the mouth of the 

 tube, remain in a perished state about the sides of the pistillum (fig. 19.) The 

 figure of the hair, while the grain is lodged in the mouth of the tube, is re- 

 markable; for the tube is then widest at the extremity, and lessens gradually as 

 far as the bifurcation, where it forms a narrow neck, which gives a bell-shaf)ed 

 figure to the superior parts, while the lower part widens again towards the base 

 (fig. 23.) In transparent styles, the ducts that lead to the germen may be seen 

 filled with corpuscles, which, being supplied in great quantities from the hairs, 

 pass on through these ducts in regular lines so close as to touch one another 

 (fig. 19.) In some inspections, the corpuscles were seen to move both in the 

 hairs and in the principal ducts of the style; which showed them to be detached 



