104 



Transact ions. 



Lycopodium Billardieri. 



The early stages of development of the prothallium in L. Billardieri 

 were not found. The mature prothallium is quite devoid of chlorophyll, 

 and consists of filaments which branch 

 rather sparingly, the formation of 

 vegetative branches taking place in 

 acropetal succession. The prothallium 

 is thickly covered with rhizoids, in- 

 clined to the axis of the branch at an 

 angle of 60 or 70 degrees (figs. 23-31). 

 The branches are cylindrical in form, 

 and growth is terminal ; but the 

 young branches are usually obovate, 

 being thicker at the distal end. The extreme ends of the branches also appear 

 lighter in colour, owing to the absence of the fungus hyphae from their cells. 



23 



Fig. 23. — Prothallium of L. Billardieri, 

 bearing young sporophyte. X 6. 



Fig. 24. — Prothallium of L. Billardieri, surrounded by detached branches. X fi. 

 Fig. 25.— Reproductive branch of L. Billardieri, bearing vegetative branches radiating 



out in all directions. X 6. 

 Fig. 20. — Prothallium of L. Billardieri, bearing young sporophyte. 

 Figs. 27, 28.— Reproductive branch of L. Billardieri, bearing young sporophyte. 



Natural size. 



The vegetative branches may grow to some length, but some become 

 thicker at their growing end and bear antheridia. After the formation of 

 antheridia has continued some time the same branch may form archegonia. 

 As soon as a branch begins to form sexual organs it gives off branches much 



