128 



THE CETPTOGAMIA OR FLOWERLESS PLANTS. 



545 547 



Seaweeds (Algie). 545, Vaucheria forming and discharging its 

 spores (a) at tlie extremities, 546, Fncns; a, air-vessei ; &, fruit, 

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

 54S, A spore with parapbases. 549, Ilydrogastrum, consisting of a 

 single ceil. 550, Spirogyrae (Frogspittle) one of the Confervie ; a, 

 two tlireads (thalli) conjugated, i, 6., united by tubes. 



such sporiferous tissues existing in 

 spots of definite form, conistitute the 

 apothecia when flat, receptacles when 

 concave, and conceptacles when hol- 

 low. 



632. The THECiE or sporangia of 

 ferns and mosses consist of tissues 

 rather than of single cells, and contain 



division of the Cryp- 

 togams into the En- 

 pores and the 

 Exospores. In the 

 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 

 (Diatoraa marinum) separating from each 

 other. 



Lichens, 530, CladAiia; the minute thallus at the ba.^6 of the podetia, cup-like above, bearing 

 scarlet conceptacles. 531, Usnea. 532, Sticta. 533, Parmelia. 584, Receptacle,' vertical sec- 

 tion. 535, A portion (highly magni&ed) with thecas aud paraphases. 636, A spore (double). 



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

 little clusters called sori. 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 spbrmatozoids are minute bodies endowed with 

 spontaneous locomotion in water by means of vibratile ciliae. Zoospores 

 of ovate form proceed from the vegetative cells of the Algfe, 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 



