Frey—Physiology of Venturia Inequalis. 
329 
of the perithecium, figs. 10, 11a and 14. The tongue-like struc¬ 
ture emerging from the coil in the perithecium and extending be¬ 
yond the margin is apparently a trichogyne. During the early 
stages the ascogonium and trichogyne seem to be non-septate, fig. 
10. After fusion with the antherids the ascogonium becomes 
septate and paired nuclei are found in the cells, although some 
figures, fig. 14, indicate that the ascogonium may become septate 
without the presnce of a trichogyne. Surrounding the trichogyne 
are numerous hyphae forming a wall around it. Most of the 
apical cells of the antheridial hyphae are swollen, have a bulb¬ 
like appearance, and arise from the filaments in the neighborhood 
of the perithecium. Some of these hyphae are applied to the tri¬ 
chogyne and seem to fuse with it, figs. 7, 8, 9, 10 and 12. Most 
of my figures show these bulb-like cells devoid of nuclei and high¬ 
ly vacuolate, as if the nuclei had migrated and the cells were dis¬ 
integrating. Occasionally multinucleate cells were found as in 
figs. 7 and 12. These figures seem to indicate that some of these 
cells function as antheridia. The antheridium is found closely ap¬ 
plied to the trichogyne and a pore is formed. Several nuclei lie 
immediately within the trichogyne and two nuclei appear to be 
within the antheridium in fig. 7. Paired nuclei are seldom found 
in the trichogyne. Apparently the nuclei migrate singly toward 
the ascogonium, but this may not always be the case for one oc¬ 
casionally finds paired nuclei in the trichogyne. The nuclei are 
approximately the diameter of the vegetative hyphae, 6-8 microns, 
and the membrane is sharply differentiated. Occasionally very 
little chromatin is visible but a large, dense nucleole is generally 
present'. Sections of the perithecium cut after fertilization has 
occurred show that the coil has become septate, and that the cells 
of the ascogonium have greatly enlarged, stain more densely and 
contain two nuclei. Figs. 8, 11 and 12 indicate that the nuclei are 
paired. Perithecia found in leaves and those taken from cultures 
compare very closely in every morphological detail during all 
the stages observed. 
In sections made from young perithecia grown on oatmeal agar 
one frequently observes the archicarp coiled but non-septate at its 
base, as in figs. 7 and 10. The trichogyne is non-septate and ex¬ 
tends beyond the perithecium. It is not definitely known at what 
stage in the development of the coil fertilization occurs. The only 
disagreement with this type of structure and the ones described 
previously by other workers is the non-septate coil. If fertiliza- 
