Britton and Tavi.ok : Liik Historv or Schizaka i'L'sili.a 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. 



Explaiiailoii of I'lates 



Plates I, 2, 3 and 4 were drawn from a niagnilkation three limes as great as ex- 

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



in the reproduction. 



Pi.ATi: I 



1. Different views uf the spore, X 80. 



2. Spore, X 140- 



3. Portion of exospore, X 333h- 



4. Ridge and fissure in exospore seen from above, X 195- 



5-17. Different stages in the germination of the spore, X S^K- ".filament; 

 /', rhizoid ; f, c, new branch. 



18. Germinating spore of Botrychium obliqunni, two weeks and five days.X h'^Vi- 

 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 ^"- "> Indication of cross- 

 wall. 



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



21. The same on August 31, X jO- 



22. On September 4, X 3°- 



23. On September 5, X 3°- 



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

 of terminal antheridium. 



25. The same with wall formed at a. 



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



(rt). h, 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 I';,. Cells of the filament dividing. 



34 and 35. Cells of the filament becoming moniliform. 



36. Voung spherical cells with the longitudinal wall («) just forming, X 80. 



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

 starting from filament at base of spherical cells /', X 80. 



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

 spherical cells ; /', rhizoids ; c, fungus in spherical cells ; d, antheridia ; e, archegonium, 



X30. 



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 195- 



