IN THE LEAF-CELLS OF ANACHARIS ALSINASTRUM. 283 



vilDvatory motion peculiar to molecular action. This also 

 occurs when there is no symptom of lotation in the cells which 

 they occupy, and in instances where the rest of the cell con- 

 tents appears to be dead. They are quite independent of the 

 active investment, and are oftentimes so numerous as to be 

 tangled together in a mass, forming a kind of nucleus, which 

 is occasionally kept in rotation by the movement of the 

 chorophyll granules. Some cells are free from them, but 

 frequently it is difficult to find one in which they do not exist ; 

 they are not " parasitic," but form one of the constituents of 

 the growth of the plant. 



I have now recorded my observations on this remarkable 

 plant ; though I am still of opinion, from the variety of the 

 phenomena displayed, that a careful series of examinations 

 will bring fresh facts to light, and that the Anacharis 

 (although denounced as a " pest") may possibly prove to be 

 one of the keys for unravelling some of the mysteries of 

 primary vegetable organization. I have entered upon the 

 inquiry without learning what has been done by others in 

 this department of microscopical investigation, and therefore 

 refrain from expressing opinions or from drawing any con- 

 clusions from the result. I only offer it as a query, with 

 respect to the elementary principle of the circulation of the 

 sap in plants. May not their growth and vitality depend 

 upon what is known as "molecular action?" I make the 

 remark, because I have observed that the sap of many dif- 

 ferent vegetable species exhibits this peculiar motion ; and I 

 would further inquire, whether the ciliary movetnent dis- 

 covered in several organisms, decidedly belonging to the 

 vegetable kingdom, may not also be a modification of mole- 

 cular action, and governed by the same exciting power? 

 For it appears to me that there are many points of analogy ; 

 and it is difficult to imagine that a single cilium, of perhaps 

 unicellular structure, and so minute as to be almost beyond 

 the limits of microscopic vision, should derive its vibrations 

 from an internal mechanism. Experiment tends to prove 

 that the acting stimulus of motion exists externally. 



I have finally to remark that this is one of those com- 

 paratively-few subjects which requires the use of large 

 apertures, and the highest powers for its investigation (I 

 have found a twelfth extremely serviceable), combined with 

 considerable care in the illumination ; for many of the pheno- 

 mena are on so minute a scale as to be classed among very 

 difficult tests. 



