HORTICULTURAL JOURNAL. 107 



and the Antlierides of the Algoe, have been worthily recompensed by the 

 great prize of natural sciences at the Institute of France. 



My learned friend having been kind enough to initiate me into some of his 

 studies, I can offer myself as a witness of the phenomena which I have just 

 noticed. I should add that* to see well the Zoospores, whose dimensions 

 scarcely attain the length of a 200th part of a milimetre, it is necsssary to 

 employ very powerful microscopes, furnished with lenses of 5 to 6 and even 

 800 diameters, which consequently produce an enlargement in volume of 512 

 millions of times. 



Besides the Zoospores, we still find in certain Algae as well as in the moss- 

 es, ferns and other cryptogamia, animalcuhe of a different nature, whose 

 presence seems necessary to reproduction, and which they have named An- 

 therozoids or Spermatozoids, on account of their analogy with the spermato- 

 zoa of animals. These spermatozoids are also furnished with vibratory- 

 threads and move with rapidity, but they die at the end of a certain time 

 without developing themselves into a new plant as the Zoospores do. The 

 faculty of germination is therefore the most proper character to distinguish 

 these last from the infusiorial animalcule, with which they have otherwise a 

 great resemblance. 



The Zoospores swim generally beak forward, sometimes they return sud- 

 denly backwards or pirouette upon themselves. They are most very sensitive 

 to the action of the light ; when we bring towards a window a vase full of 

 water and containing Zoospores, we see them direct themselves rapidly to 

 the lighter side : at other times on the contrary they seem to fly the light 

 and hide themselves the darkest place. Their vibratory movements last for 

 several hours, often even many days, before germination commences. We 

 can, as I have said, stop them instantly by means of acid, alcohol, ammonia 

 or iodine ; opium having a less prompt action, quiets their movements gradu- 

 ally and permits us to distinguish the play of the threads. 



Besides the faculty of moving, the Zoospores have besides that of contrac- 

 ting ; thus we see that being stopped by the middle of their bodies during 

 their exit from the tube, they curve their anterior extremity from one side to 

 the other and contract violently in every direction, until they have over- 

 come the obstacle which stops them. But, lately, after vainly sought a char- 

 acterwhich could serve to distinguish definitely plants from animals, we have 

 thought that we should regard contractibily as the exclusive apanage of the 

 latter. The Zoospores which by their germination faculty evidently belong 

 to the vegetable kingdom by properties which are even more evident in thera 

 than in many infusorial animalcule. " The extreme analogy of lower ani- 

 mate and vegetables does not then permit us to trace a precise line of. demar 



