107 



oospore ; 9, Germinating oospore ; 10, Contents of the germi- 

 nating oospore divided into four parts; 11, Four zoospores in 

 the interior of the germinating oospore ; 12, Young plant (figs. 

 2-12 x 2500). 



PLATE VIII. Cosmarium botrytis. 1-3, Multiplication by 

 division ; 4, Full-grown individual, with numerous oscillating 

 granules in the clear vacuoles. 



PLATE IX. Chara fragilis. 1, Part of a plant in fruit 

 ( x 10) ; 2, Part of a young leaf with antheridia and archegonia 

 ( x 82) ; 3, Part of a fertile leaf with almost ripe spore-bud 

 ( x 400) ; 4, Ripe oospore ( x 200). 



PLATE X. Cystosira barbata. 1, Plant at the time of fructi- 

 fication ; 2, Part of a fructifying branch ( x 6) ; 3, Transverse 

 section of the same ( x 120) ; 4, Group of antheridia ripe and 

 unripe ( x 1900) ; 5, 6, Ripe oogonia (x 1900) ; 7, Germinating 

 oospores ( x 486). 



PLATE XI. Polysiphonia subulata. 1, Part of a female 

 plant ( x 84) ; 2, Ripe antheridium ( x 2000) ; 3, Portion of 

 thallus with carpogonium undergoing fertilisation ; 4, Ripe cys- 

 tocarp with escaping spores ( x 600) ; 5, A, B Germinating 

 spore, two stages ( x 900 and 2400) ; 6, Portion of a branch with 

 tetragonidia (x 480); 7, Stages in the germination of the 

 tetragonidia ( x 600). 



PLATE XII. Mucor Mucedo. 1 , Full-grown mycelium ( x 1 5 0) ; 



2, Stalk with unripe sporangium ( x 1800) ; 3, Ripe sporangium 

 ( x 1000) ; 4, Stalk with remairs of ruptured sporangium 

 (x 1800) ; 5, 6, Germinating spores ( x 6600). 



PLATE XIII. Peziza. 1, a, b, Fructifications of Peziza 

 aurantia ( x 3%5) ; 2, Section of one of the fructifications ( x 44) ; 



3, Part of a longitudinal section ( x 550) ; 4, Part of the hymenial 

 and sub-hymenial layers with asci ( x 2400). 



PLATE XIV. Endocarpon pusillum. 1, Plant seen from above 

 ( x 46) ; 2, Thallus five months old ( x 46) ; 3, Vertical section 

 with ripe fruit ( x 800) ; 4, Single spore with hymenial gonidia 

 attached ( x 2700) ; 5, Two spores germinating ( x 2700) ; 6, 

 Germinating spore further advanced ( x 2700) ; 7, Rudimentary 

 thallus (x 2700); 8, Fresh hymenial gonidia ( x 4100); 9-11, 

 Gonidia of various forms and ages ( x 4100). 



PLATE XV. Puccinia graminis. 1, Germinating teleutospore 

 ( x 2500) ; 2, Young leaves of barberry (Berberis vulgaris) with 

 secidia ( x 1) ; 3, Transverse section of barberry leaf with ripe 

 secidium (x 270); 4, Germinating secidiospore (x 1350); 5, 

 Wheat stalk (Triticum vulgare), with ears attacked by rust 

 ( x 2) ; 6, Transverse section of wheat-leaf attacked by rust 

 ( x 1000) ; 7, Layer of uredospores with teleutospore ( x 1300) ; 

 8, Layer of teleutospores in couch grass (Triticum repens) ( x 500). 



