Britton and Taylor : Life History of Schizaea pusilla 17 



trichomes. Warts or swellings occur from the epidermal cells on 

 both surfaces, though more numerous on the ventral side. 



The bundles appear collateral with a well-marked endodermis. 

 The mesophyll tissue is composed of thin-walled cells, branched 

 in a stellate manner. 



Explanation of iMates 



Plates i, 2, 3 and 4 were drawn from a magnification three times as great as ex- 

 pressed in the numbers which represent the magnification of the figures as they stand 

 in the reproduction. 



Plate i 



1. Different views of the spore, X &°* 



2. Spore, X I 4°- 



3. Portion of exospore, X 333/i- 



4. Ridge and fissure in exospore seen from above, X I 95* 



b, rhizoid ; c, c, new branch. 



58 l A. a y filament; 



nd five days,X S^ l A 



Sown at same time as Schizaea spores. The last-named did not start to germinate un- 

 til after three weeks. 



19. Germinating spore found in soil on August 28, X 80. a, Indication of cross- 



wall. 



20. The same on August 29. a, cross- wall formed. 



21. The same on August 31, X 3°- 



22. On September 4, X 3°- 



23. On September 5, X 3°- 



24. Spore found in soil on September 5, X 3°- a i antheridia ; b^ swelling at base 



of terminal antheridium. 



formed 



26. Filament of four cells with antheridium showing mother-cells of antherozoids 



{a). b 9 Rhizoid, X 80. 



27. Sporangium with spores germinating inside, X 3°- Owing to position in 

 which the sporangium fell when sown — the filaments from the spores are not sent out 

 though the regular fissure at a. 



Plate 2 



28. 29, 30 and 31. Methods of branching of the protonemal filaments. 

 32 and 33. Cells of the filament dividing. 



34 and 35. Cells of the filament becoming moniliform. 



36. Young spherical cells with the longitudinal wall (a) just forming, X &>• 



37. Older stage of the same showing young rhizoids (a, a) and young branch 

 starting from filament at base of spherical cells b f X 80. 



38. Portion of filament showing spherical cells, antheridia, and archegonia. a, 

 spherical cells ; 6, rhizoids ; c> fungus in spherical cells ; d 9 antheridia ; e 9 archegonium, 



X3<>. 



39. Shows position of spherical cells, X 3°- 



40. Abnormal condition. One cell of the filament giving rise to one spherical 

 cell, and a cell of the filament next above giving rise to two, X 3°- 



41. End of rhizoid showing fungus penetrating into the cell. Shaded portions 

 are hyphae which are inside the rhizoid, X I 95- 



