128 



THE CRTPTOGAMIA OR TLOWERLESS PLANTS. 



545 04T 



Seaweeds (A!g;e). 545, Vaaclieria forming and di8charp:in!r its 

 sfinres (3) at the extremities. 546, Fucus; rt, air-vessel; ft, frnit, 

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

 543, A spore with paraplaases. 549, Hydrofcastnim, consisting of a 

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

 two threads (tballi) conjugated, 4. e., united by tubes. 



such sporiferous tissues existing in 

 spots of definite form, constitute the 

 apothecia when flat, receptacles when 

 concave, and conceptaclcs when hol- 



divisionof t^ie 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 licht'iia ' 



632. The thec^ or sporangia of 

 ferns and mosses consist of tissues 

 rather than of single cells, and contain 



551, Frustules of a, Diatomaceous Ah 

 (Diatoma marinum) separating from eac 

 other. 



Lichens, 530, Cladonia ; the minute thallus at the base of the podetia. cup-lilce 5bove, bearing 

 scarlet conceptaclcs. 531, LTsnea. 532, Sticta. 533, Parmelia. 534, Ueceptacle, vertical sec- 

 tion. 535, A portion (highly magnified) with thecffi and paraphases. 536, 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 spermatozoids 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 Alg», 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 



