Frey—Physiology of Venturia Inequalis, 
341 
Plates X and XI 
Pig. 1. Beginnnig of coil which results in a perithecium. 
Fig. la. Shows conjugation of adjacent filaments. 
Pig. 2. Formation of coil. 
Fig. 3. Coil enlarging; enveloping hyphae being formed. 
Fig. 4. Early stages in coil formation. Observed in Van Tieghem cell. 
Pig. 5. Large branch which forms the coiled ascogonium has bulb and club 
shaped hyphae applied to it. 
Fig. 6. Section of a coil. The nuclei are enlarged. 
Pig. 7. Club shaped cells, the antheridia, applied to the trichogyne. A pore 
is evident in the trichogyne. 
Fig. 8. The ascogonium has become septate and consists of several cells, one 
of which is shown. The nuclei migrate down the trichogyne singly and 
later pair in the ascogonium. 
Pig. 9. Section of a perithecium showing the coil after fertilization has oc¬ 
curred. 
Pig. 10. Section of young coil. 
Fig. 11a. Section of perithecium after fertilization showing trichogyne and 
coiled ascogonium. The nuclei are paired in the cells of the ascogonium 
but not in the trichogyne. 
Pig. 11b. Another section of perithecium shown in Fig. 11a. The re¬ 
mainder of the coil is evident. 
Fig. 12. Section of a perithecium. The ascogonium has several cells, each 
with paired nuclei. The nuclei of the trichogyne are not paired. The 
pore through which the male nuclei entered the trichogyne is visible. 
Pig. 13. Section of a perithecium showing paired nuclei in the cells of the 
ascogonium. 
Fig. 14. Section of young perithecium. The ascogonium is multicelled as 
in the previous figures. The trichogyne was not found. 
Pig. 15. Section of a young perithecium at the time of fertilization. The 
nuclei are paired but the ascogonium has not become septate. 
Pig. 16. Section of a perithecium. The paired nuclei appear to be fusing. 
The trichogyne is disintegrating. The cells of the ascogonium appear to 
be branching in preparation for ascus formation. 
Fig. 17. Section of perithecium shown in Fig. 16. Note paired nuclei in the 
cells which later form asci. 
Fig. 18. Section of perithecium. Branching and budding of the ascogenous 
cells is taking place. 
Fig. 19. The coil of the ascogonium is reorganizing. New cells are being 
formed either by budding or by cell division. Nuclear division is taking 
place. 
Fig. 20. In place of the coil of the ascogonium there are a large number of 
cells. From these compact cells branches arise which later form asci. 
Pig. 21. Cells in which nuclear fusion seems to be taking place. 
Fig. 22. Section of perithecium showing formation of many small cells, which 
later develop asci, from the coil which originally consisted of five or 
six cells. 
Pig. 23 a, b, c. Similar to Fig. 22. 
Pig. 24. Section of mature perithecium. Asci are being formed. 
Pig. 25 a, b. Section of perithecium showing asci. 
