VASCHLAa FLOWERLESS PLANTS. 89 



these organs is more highly magnified at p, and exhibited so 

 as to show the attachment of the theeaa to its lower surface; 

 t, a separate theca, still more magnified j r and v are the 

 spores, with the clavate filaments, which are shown rolled in a 

 spiral around the spore r, and spread out from the spore v. 



128. Struck hy the analogy of form which exists between 

 the reproductive organs of the Equisetacese and the stamens 

 of some Coniferae, Linnseus named these clavate filaments 

 stamens, without indicating those which he regarded as pistils. 

 Hedwig, on the contrary, considered these bodies as herma- 

 phrodite flowers, the globular part being the pistil and the 

 filaments the stamens, the pollen being situated on their ex- 

 terior surface. But these filaments are certainly analogous 

 to the elaters of Jungermannia. These spores are first 

 formed in the interior of the cells, the walls of which, in 

 place of being absorbed, remain attached to the spores in the 

 form of elaters. 



129. When moist, these filaments are twisted spirally 

 around the central spore,; but, when dry, they unroll and 

 expand elastically, thus moving the spore along with them in 

 various directions. If a spike of the Equisetum, when ripe, be 

 shaken over white paper, the spores will appear like brown 

 powder on its surface; and if we gently breathe on them, and 

 examine them at the same time with a magnifier, they will 

 be seen crawling about the paper like so many little spiders. 

 This circumstance arises from the hygrometrio property of 

 the elaters which are affixed to the spores and possess this 

 property in order to efieet their dissemination, 



130. All the species of Equisetaceas are, with us, perennial 



