on species of Tolypoihrix. 
66 3 
DESCRIPTION OF FIGURES IN PLATE XXIX. 
Illustrating Dr. Fritsch’s paper on Fungi parasitic on Tolypothrix . 
Figs. 1-18. Resticularia Boodlei , n. sp. 
Fig. i. Two spores, lying in the membrane of the Tolypothrix , from which 
epiphytic hyphae have arisen, x 600. 
Fig. 2. A spore has germinated, giving rise to a short endophytic mycelium, 
x 600. 
Fig. 3. Fully-developed parasitic hypha, showing moniliform constrictions ; at 
a, an external branch is developing, x 750. 
Fig. 4. The same ; shows a further stage in the development of the external 
branch, x 750. 
Fig. 5. A spore has germinated at both ends ; one of the hyphae thus formed 
has penetrated a filament of the Alga, giving rise to a parasitic, moniliform hypha 
in both directions. From the internal mycelium an infecting-hypha has branched 
off. x 750. 
Fig. 6. A spore has germinated; the parasitic mycelium has formed three 
infecting-hyphae. x 750. 
Fig. 7. Oily granules are seen in the mycelium ; also an infecting-hypha. 
x 750. 
Fig. 8. The Fungus has died off behind and has become septate in the dead 
portion ; in front the mycelium is not constricted, but forms a straight tube, x 750. 
Fig. 9. Spore germinating; the penetrating hypha has spread out in both 
directions along the algal filament. The latter has formed thick protecting-walls, 
a little way in front of the present position of the parasite, x 750. 
Figs. 10, 11. Infection from one individual of the host to another. The dead 
posterior portion of the parasite has become septate, x 750. 
Fig. 12. Reinfection of same filament ; see explanation in text, x 750. 
Figs. 13, 14. Evasion of the protecting-walls formed by the Alga, x 750. 
Fig. 15. Reinfection and fusion; see explanation in text, x 750. 
Fig. 16. Formation of spores on the external mycelium, early stages. The 
arrow indicates the point at which the main hypha continued and joined on to the 
endophytic mycelium, x 750. 
Fig. 17. The same; further advanced stage. The entire external mycelium has 
given rise to spores, x 560. 
Fig. 18. At sp. internal spores are possibly developing, x 750. 
Figs. 19-29. Resticularia nodosa , Dangeard (?). 
Fig. 19. This shows the ordinary appearance of the parasitic mycelium, which 
terminates at one of the heterocysts of the Alga. The cell-contents of the latter 
are contracted about the Fungus, x 600. 
Fig. 20. The same ; a chlamydospore has developed within the heterocyst, x 600. 
Fig. 21. A chlamydospore is developed in the course of the internal mycelium, 
x 600. 
Figs. 22, 23. Show chlamydospores ; in Fig. 22 they alone remain, x 600. 
Z Z 
