Dr. A. Grisebach on Phytozoa in Phanei-ogamous Plants. 265 



are not situated on the surface of the germinating leaf, but sunk 

 into its margin. Its position therefore as regards other ferns is 

 exactly in the same relation as the development of the spores on 

 the frond, which in general are situated on the surface, but in 

 Adiantum are on the margin. Now although in this case the 

 corynidia by no means project freely from the cellular tissue of 

 the germ-leaf, there will be seen, just as in all other cases, an outer 

 layer of cells, differing in the present instance by the absence of 

 chlorophylle globules from the other adjacent cells, and leaving the 

 inner sac in which the minute free cells occur, every one of which 

 encloses a phytozoon. The structure therefore is perfectly similar 

 to the antheridia of mosses, and I have found it precisely as de- 

 scribed by Nageli : the same with respect to the form of the phy- 

 tozoa, but not the motions, which I am not able to distinguish 

 from inorganic molecular motions. 



The occurrence of phytozoa in decidedly vegetative parts of 

 plants increased my hope of detecting them in Phanerogamia. I 

 had frequently observed, in the investigation of leaf-buds, masses 

 of black particles in the drop of water on the glass stage, which 

 exhibited on being magnified 200 times a very lively molecular 

 motion. Their origin was unknown to me, but on recently ob- 

 serving them again in the buds of Rhamnus infectoria and pumila, 

 I immediately observed most distinctly with a magnifying power 

 of 41 that they were phytozoa accurately agreeing with those in 

 ferns. Like them they consist of long-tailed globules which are 

 individually inclosed in a very minute spherical cell, or swim freely 

 about in the water, oscillate in a lively manner, and sometimes 

 move the tail. Since there was no doubt of the identity of this 

 phsenomenon, it now only remained to see whence these globules 

 were derived. The place where the corynidia are situated was 

 soon found, and it now became evident that exactly the same 

 apparatus occurs here as in the ferns and mosses. In the Rham- 

 neae the stipules are formed very early, and we consequently find, 

 even in the youngest parts of the leaf-bud, each leaf inclosed be- 

 tween two membranous stipules projecting beyond it and arising 

 from a common basilary membrane : this, it may be observed en 

 passant, is an argument in favour of Robert Brown^s view that 

 the Rhamnea should be placed near the Malvacece, which exhibit 

 the same development of stipules, while the CelastrinecBy as I find 

 at least in Euonymus, form their teguments from leaves and only 

 obtain stipules very late. At the basis of the two stipules in 

 Rhamnus, on the upper surface, is situated a group of clavate 

 bodies, which agree perfectly in their structure with the corynidia 

 of ferns and mosses, and like these, the phytozotic cells discharge 

 their contents by endosmosis. This phsenomenon is quite common 

 in leaf-buds with dormant vegetation. Where no stipules exist, 



Ann. ^ Mag. N, Hist. Fo/.xv. U 



