EXPLANATION OF TLATE XL [continued). 



Fig. 



22. Arcyria cinerea, Fries. — A single sporangium, completely filled with half- 



matured spores, X 25. 



23. Phlebomorpha rufa, de Bary, — Portion of horny rete or capillitium, with 



enclosed spores, x 390. 



24. DiDYMlUM serpula, Fries. — Section of sporangium, showing contained 



spores. 



25-28. Lycogala epidendron, Fries. — 25, Two isolated spores ; the one at a bursting 

 and liberating its monadiform germ, x 390 ; 26, three fully developed, free- 

 swimming, highly polymorphic monadiform zooids, developed from the 

 spores represented in the preceding figure, x 390 ; 27, amceboid condition 

 assumed by the same monadiform zooids, representing the first step towards 

 the development of the compound plasmodium ; 28, Young repent amoebi- 

 form Plasmodium formed by the coalescence of several of the smaller 

 amoeboid particles. 

 29. yExHALlUM SEPTICUM, Fries. — Young repent plasmodium, x 200. 



30, 31. DiDYMlUM FARINACEUM, Fries. — 30, Fragment of peridium or indurated outer 

 wall of sporangium, containing substellate calcareous spicula, x 390; 31, an 

 isolated spicule from the same peridium further enlarged. 



32-35. DiDYMlUM SERPULA, Fries. — 32-34, Polymorphic monadiform zooids, the 

 example at 32 with ingested food-particles ; n, nucleus or endoplast ; c v, con- 

 tractile vesicle, x 350; 35, amoebiform condition of a similar monadiform 

 zooid, X 350. 



36-38. Trichia varia, Pers. — 36, Isolated spore, x 390 ; 37 and 38, the same spore 

 with its wall ruptured, and giving exit to a free-swimming monadiform 

 zooid. 



39. DiDYMlUM LiBERTlANUM, Fries. — Minute subaqueously developed sporangium, 

 with nine or ten contained spores, x 390. 



40-44. Stemonitis obtusata. Fries. — Successive phases of multiplication by fission 

 of a monadiform zooid, x 390. 



45-47. DiDYMlUM LEUCOPUS, Fries. — Young repent amoebiform plasmodia, containing 

 [c V, V c) numerous contractile vesicles, the plasmodia at 45 and 46 being 

 in a contracted, and at 47 in a fully extended state, x 350. 



