ORGANS OF REPRODUCTION. 377 



reduced to two or three elongated cells. The spermatia are ter- 

 minal on the spermatophores, and consist of exceedingly minute 

 bodies, ordinarily linear, very thin, short or longish, straight or 

 curved, without appendages, and motionless, and lie in a muci- 

 lage of extreme transparency. These spermatia are commonly 

 regarded as the analogues of the spermatozoids produced in the 

 antheridia of the higher Cryptogams," When the spermagonium 

 is mature, the spermatia are discharged thro-agh the pore or 

 ostiole in vast numbers {fig. 825). 



Besides the above reproductive organs of Lichens, there are 

 also to be found, in some genera, certain round cells called 

 gonidia, which are filled with a green substance : these are capable 

 of reproducing the plant when detached, and appear, therefore, 

 to be analogous organs to the buds of the Phanerogamia. Some- 

 times these gonidia, by increasing at certain parts of the thallus, 

 make their way to the surface and appear as little masses of 

 dust, which are called soredui. Dr. Hicks and other botanists 

 have recently proved that many of the bodies regarded hitherto 

 as unicellular Algae are in reality tjransitory conditions of these 

 gonidia. 



2. Fungi or Mushrooms. — This order is remarkable for the 

 great development of its reproductive apparatus, which in most 

 cases constitutes the principil portion of the plant. This repro- 

 ductive structure varies very much in the different divisions of 

 this vast group of plants, and as many points connected with it 

 are at present but imperfectly known, we can only very briefly 

 allude to it here ; iadeed, with regard to the Fungi generally, it 

 may be observed that our knowledge upon many points is be- 

 coming rapidly enlarged, so that much of what may be now 

 written will probably soon require modification. 



The nutritive structure of Fungi consists of coloiirless, deli- 

 cate, jointed, anastomosing filaments, called the raycd'mm or 

 spawn ( figs. 4 — 6,) which corresponds to the thallus of other 

 Thallogens. 



From the researches of M. Tulasne, it would appear, that the 

 reproductive organs of Fungi are at least of three kinds> namely, 

 1. Spores, either naked (fig. 828, sjw) ; or enclosed in cases, 

 called thccxB, asoi, oysHdia, ov sporangia {fig. 829), and which are 

 supposed to represent the female apparatus; 2. Spermatia {fig, 

 830), which are either developed among the spore-producing 

 bodies, or on different parts of the plant. They are sometimes 

 found in distinct receptacles like those of Lichens, which are 

 accordingly termed spcr-magonia {fig. 830). These spermatia 

 have been supposed by some to be the analogues of the anthe- 

 rozoids or spermatozoids found in the antheridia of the higher 

 groups of Cryptogamous Plants, and hence to represent the male 

 apparatus, but their functions are as yet by no means clearly 

 ascertained ; and 3. Siylospores enclosed in pt^cnidia. 



