344 ELEMENTARY ORGANS. CHAP. III. 



they may be emptied, at least in part, by means of 

 pressure. 



Additional B u t if this were not the case. I think the tubular 

 proofs. 



structure of the longitudinal fibres might be de- 



monstrated even from other facts. Having taken 

 the peduncle of a male flower of Marchantia poly- 

 morpha and pulled it gently in two, I found that 

 the central and longitudinal fibre had not been 

 fractured at the point, where the rest of the pedun- 

 cle was fractured, but at the distance of about an 

 inch. The consequence was, that it was drawn out 

 of the surrounding substance as out of a sheath, 

 and laid bare to the above extent. It was perfectly 

 colourless and transparent, and what appeared to 

 the naked eye to be but one fibre, was found under 

 the microscope to be composed of a number of 

 smaller fibres amounting at least to twelve, perhaps 

 twenty, and closely adhering together by the whole 

 of their length. In these I could plainly perceive 

 'the existence of a fluid, which was in some ascend- 

 ing and in others descending with a quick but in- 

 terrupted motion, like that of the mercury in a tube 

 that has not been well cleaned, or of the air in a spirit 

 of wine level. From this I think the tubular struc- 

 ture of the longitudinal fibres, together with their 

 capacity of conducting fluids, is clearly demon- 

 strated ; as well as from the visibility of their aper- 

 ture on the transverse section. 

 Observa- Leuwenhoeck, who was a great advocate for the 



lions of 



Lenwen- vasqular v structure of the vegetable fibre, pursued 



boeck. 



