Miscellaneous. w^ 



"When these organs are kept iu separate vessels, the following pnee- 

 nomena are observed. The antheridia immediately emit their anthe- 

 rozoids, which move about with the greatest vivacity ; these move- 

 ments are frequently continued till the next day, diminishing gra- 

 dually in intensity ; on the third day decomposition commences. The 

 spores remain for about a week without sensible alteration ; they 

 then also decompose without further development. Sometimes phse- 

 nomena resembling germination are exhibited ; some of them emit 

 irregular prolongations, but no septa are formed ; the evolution of the 

 spores proceeds no fiirther ; they become decomposed like the others. 

 In fact, germination never takes place in spores which are deprived 

 of the contact of the antherozoids. 



But when the spores and the antheridia are mixed together, the 

 spore becomes invested \\'ith a very distinct membrane in the course 

 of a day or two, a septum is formed which divides the spore into two 

 hemispheres, and a sensible elongation begins to appear on a point of 

 the circumference. The development of the young plant then pro- 

 ceeds rapidly ; the septa become more numerous, the elongation 

 increases, and in about ten days the spore is converted into a small 

 ovoid, cellular mass, of a brown colour, supported on a transparent 

 radicle. 



If the experiment has been performed on a sUp of glass kept con- 

 stantly near a window in the same position, it will be seen that nearly 

 all the radicles are turned towards the interior of the room, or from 

 the light. 



The fecundating action of the antherozoids upon the spores is 

 therefore an incontestable fact. When they are in considerable quan- 

 tity, they frequently attach themselves to the spores, crawl in a man- 

 ner upon their surface, and communicate to them, by means of their 

 vibratile cilia, a rotatory movement which is often verj- rapid. 

 Nothing is more curious than the appearance of these large brownish 

 spheres rolhng in all directions amongst the crowds of antherozoids 

 which surround them. This phaenomenon, however, does not appear 

 to be necessary for the fecimdation of the spores. \Mien all move- 

 ment has ceased and germination has commenced, the remains of 

 decomposed antherozoids frequently surround the spore without 

 being immediately in contact with it ; a layer of mucilage separates 

 them from the membrane of the spore and forms a transparent halo 

 around it. 



The author endeavoured to fecundate the spores of Ozothallia vul- 

 garis {Fucus nodosus, Linn.) with the antherozoids of Fucus ser- 

 ratus and vesiculosns, and vice versa. But although the spores and 

 antherozoids of these three species present the most complete re- 

 semblance, and although the antherozoids attach themselves m. great 

 numbers to the spores, causing them to move mth great vivacity, no 

 grm nation took place. Nor did he succeed in fecundating the 

 spores of Fucus serratits with the antherozoids of Fucus vesieulosus. 

 But on reversing this experiment, some of the spores of the F. vesicu- 

 losns germinated. He does not venture to conclude from this that a 

 hybrid fecundation is possible, but nevertheless calls attention to the 

 ' Ann. &)• Mag. N. Hist. Ser. 2. Vol. xii. 5 



