Fructification of the Genus Chdra, 349 



to examine this singular phenomenon with the minute attention 

 which it deserved ; but I made a rough sketch of the appear- 

 ance, intending on some future occasion to renew my observ- 

 ations. I have, however, since sought in vain for fresh ex- 

 amples ; and, as I think it possible that the appearance may 

 have originated in some accidental obstruction in the tubes of 

 these specimens, preventing the passage of the red matter 

 through some of them, I wish the fact to be made known at 

 once, in order that others may have their attention called to 

 the subject, and not neglect an opportunity, should they 

 chance to meet with one, of examining a phenomenon, which 

 seems so likely to afford us further insight into the real cha- 

 racter of the fructification of these plants. 



The fact which this appearance seems to me to establish 

 is, the internal passage of the red matter from the globule to 

 the nucule, affording us a strong point of analogy between 

 this genus and the Confervae conjugatae ; an analogy, however, 

 which has not been overlooked in the general structure of the 

 plants themselves. How the red matter passes from the outer 

 coat to the inner chamber of the nucule is not so apparent; 

 unless we may suppose it to be effected through certain minute 

 connecting processes, detected in the fossil species of this 

 genus, figured by Mr. Lyell in the Geological Transactions 

 (new series, vol. ii. pi. 13. fig. 2.). I have found, upon opening 

 some nucules which had fallen from the plant, that they were 

 filled with perfectly smooth spherical grains of considerable 

 size, and of a reddish tinge ; and that these grains were com- 

 posed of a congeries of minute granules. These grains are, 

 probably, what some observers have imagined to be seeds, and 

 who have in consequence described the nucule as a polysper- 

 mous capsule ; whilst others, who have seen that each nucule 

 produces only one plant, have considered these grains to be 

 of an alimentary nature, prepared for the purpose of nourish- 

 ing the young plant during the early stages of its germination. 

 If we were to allow that any analogy exists between the Charas 

 and phaenogamous plants, the globule would rather seem to 

 represent a single naked grain of pollen than an entire anther, 

 as it has been usual to consider it : but in our present igno- 

 rance of what are the actual functions of this organ, it is per- 

 haps safer to class this genus with the Cryptogamia. 



I am. Sir, yours, &c. 

 Cambridge, Feb, 2. 1832. J. S. Henslow. 



To the charas another very interesting consideration appertains: for 

 within their pellucid stems, when inspected through a powerful microscope, 

 the motion of the sap, in its course of circulation, is as obvious as the cur- 

 rent of a river. I had the pleasure to witness this, as had several others, 



