254 



When the spore is ripe it has a wrinkled appearance ; on the addi- 

 tion of water its size is considerably enlarged and the wrinkles disap- 

 pear. A curious effect is produced on tincture of iodine being added 

 to the water ; the nucleus of the spore " is contracted to a much 

 smaller size, leaving the outer membrane occupying the space to which 

 it had been distended by the water, and appearing under transmitted 

 light like a transparent limb to the opake spore." The minute gra- 

 nules in the spore are said to be " exactly similar to those contained 

 in the pollen-grains of flowering plants ; " and the author is of opin- 

 ion that they are of the same nature as the smaller granules on the in- 

 tegument and in the spaces between the cells of the theca ; he also 

 finds that the larger granules are soluble in boiling water though not 

 in alcohol ; water does not dissolve the smaller ones, and alcohol pro- 

 duces no other effect on them than to suspend their motion. Iodine 

 imparts to the larger granules a bluish colour, but produces little or 

 no effect on the small ones. 



Both kinds of granules have been found by the author in the unripe 

 thecEB of ferns, of Lycopodium and of Ophioglossum ; he has also ob- 

 served active granules in the unripe thecae of mosses and several spe- 

 cies of Jungermannia, in the apothecia of lichens, in the lamellae of 

 Agarics and the perithecia of some other Fungi. 



" On comparing these granules with those contained in the unopened anthers of 

 flowering plants, they appear to me to be in every respect identical ; in both cases, 

 where the larger ones occur, they are similarly acted upon by iodine, and are therefore 

 probably of the same nature ; in the theca they appear to occupy a similar place with 

 those in the cells of the anthers, and they decrease in like manner during the progress 

 to maturity of the pollen-grain and of the spore. In the granular contents of the spore 

 also there is the most perfect resemblance to those of the pollen-grain. Perhaps the 

 most obvious difference is in the entire absence of green colour from the fluid of the 

 latter."— p. 671. 



The paper concludes with a detail of the changes which take place 

 in the organization of the theca during the progress of the spores to 

 maturity ; and the descriptions are illustrated by figures. 



Art. XLIII. — Account of two neiv Genera allied to Olacinese. By George 

 Bentham, Esq., F.L.S. 



The two species on which Mr. Bentham has founded one new ge- 

 nus, Pogopetaliun, are among the plants collected by M. Schombm-gk 

 in British Guiana : and fine specimens of another genus, named Apo- 

 dytes dimidiata by Ernst Meyer in Drege's plants, but first described 

 in the present paper, are in a collection from Port Natal, in South 



