128 



THE CRYPTOGAMIA OR FLOWERLESS PLANTS. 



546 



549 



545 517 



, Seaweeds (Alg;e). 545, Vaucheria forming and discharging its 

 spores (a) at the extremities. 546, Fucus; a, air-vessel; &, fruit, 

 a mass of conceptacles. 547, Transverse section of a conceptacle. 

 543, A spore with paraphyses. 549, Ilydrogastrnm, consisting of a 

 single cell. 550, Spirogyrae (Frogspittle) one of the Confervas ; a, 

 two threads (thalli) conjugated, i. e., united by tubes. 



such sporiferous tissues existing in 

 spots of definite form, constitute the 

 apothecia when, flat, receptacles when 

 concave, and conceptacles when hol- 

 low. 



632. THE THEC^ OR SPORANGIA of 

 ferns and mosses consist of tissues 

 rather than of single cells, and contain 



division of the Cryp- 

 togams into the En- 

 dospores and the 

 Exospores. In tho 

 latter case the pa- 

 rent-cells are called 

 basidia, and many 

 such united, as in 

 the lichens and 

 mushrooms, form a 

 tissue called hyme- 

 nium. In lichens 



551, Frustules of a Diatomaceous Alga 

 (Diatoma marinum) separating from each 

 other. 



530 



535 536 533 



534 532 



Lichens, 530, Cladonia; the minute thallus at the base of thepodetia, cup-like above, bearing 

 scarlet conceptacles. 531, Usnea. 532, Sticta. 533, Parmclia. 534, Keceptacle, vertical sec- 

 tion. 535, A portion (highly magnified) with thecae and paraphases. 536, A spore (double). 



numerous spores. In ferns they grow on the back of the fronds in 

 little clusters called son'. When mature, the sporange is torn open by 

 the contraction of an elastic ring which surrounds it. In the mosses 

 the sporange is stalked, solitary, terminal, and opens by a definite num- 

 ber of teeth called the peristome. 



633. ZOOSPORES AND spERMATOzoiDS are minute bodies endowed with 

 spontaneous locomotion in water by means of vibratile cilise. Zoospores 

 of ovate form proceed from the vegetative cells of the Algae, swim 

 about for a time, then settle down and grow into new plants. Sperma- 

 tozoids are mostly filiform bodies with several ciliae, discharged from the 



