398 Blackman and Welsford. — Parasitism. //. 
Fig. 5. Germinating spore mounted in a colloidal solution of silver; the "mucilage sheath is 
clearly visible, x 1,200. (Leitz water-immersion objective.) 
Fig. 6. Young germinating spore attached to epidermis of a leaf which has been already 
infected elsewhere ; the epidermal wall has swollen owing to this infection, x 1,200. 
Fig. 7. Young germinating spore anchored to the leaf surface, x 1,200. 
Fig. 8. Group of germinating spores ; one germ tube is exerting sufficient pressure to push the 
wall inwards, x 1,200. 
Fig. 9. Young germinating spore : the germ tube has begun to spread out on the epidermis to form 
an appressorium ; the wall of the germ tube is slightly altered at the place of contact, x 1,200. 
Fig. 10. Young germinating spore lying on cuticle and pressing it slightly inwards, x 1,200. 
Fig. 11. Young hypha swelling out at end to form an appressorium. x 1,200. 
Fig. 12. Appressorium forming at the end of a hypha. The wall at the apex of each branch 
is slightly modified. x 1,200. 
Fig. 13. Young appressorium showing mucilaginous sheath. Drawn from fresh material, 
x 1,200. 
Fig. 14. Young plant of Botry/is with a very small appressorium; the outgrowth has just 
passed through the cuticle of a previously infected leaf, x 1,200. 
Fig. 15. Tip of hypha pressing wall of epidermal cell inwards. X 1,200. 
Fig. 16. Ditto, x 1,200. 
Fig. 17. Two young Botrytis plants which are surrounded by shrunken remains of dehydrated 
mucilage. One plant has pushed through the cuticle by a small peg and is spreading out in the 
subcuticular layer ; the second plant is already growing in the swollen wall. x 1,200. 
Fig. 18. A hypha which is growing in the subcuticular layer of the epidermal wall, x 1,200. 
Fig. 19. A group of appressoria. The pore by which the hypha has entered the subcuticular 
wall is shown. In this case the wall was specially stained to show the laminate structure of the swollen 
wall. Other hyphae have already entered the leaf, x 1,200. 
Fig. 20. Group of appressoria ; the small pore through which entrance is effected is shown. In 
this case the hypha has gone straight through the epidermal cell. X 1,200. 
Fig. 21. A hypha which has penetrated the leaf by means of a small pore; it has continued to 
grow downwards through the cell, but has caused no swelling of the wall, x 1,200. 
Fig. 22. A portion of a transverse section of a leaf. A hypha has penetrated the cuticle and is 
growing in the outer epidermal wall ; the nucleus of the cell has an amorphous appearance. The 
nuclei of the two cells immediately below have moved upwards in response to a stimulus caused by 
the intruding hypha. x 450. 
