11 



the spores obtained and those sown. The 

 difference is shown in the illustrations. 

 The spores as originally found on the guava 

 were loosely granular and the vacuole was 

 not very conspicuous. The generation on 

 the apple was more finely granular, and 

 the vacuole was more clearly to be seen. 

 My notes, made at the time, say that the 

 spores had varied in the direction of the 

 form of the Gloeosporium spores as 

 ordinarily found on the apple in nature. 

 After sixteen days the rotten area was three- 

 fourths of an inch across, and some of the 

 pustules had begun to emit " tendrils." 



17. PEAR inoculated from the Gloeo- 

 sporium of the Guava. In eleven days the 

 pear was half rotten, but without any 



^spsw^i 1 Fig. 20. Spores of the Gloeo- 

 sporium, obtained from 

 inoculating a pear with 

 spores of the Gloeosporium 

 found growing naturally on 

 the guava. 



x4oo 



definite outbreak of pustules. The rot 

 seemed too soft for ripe rot. No pustules 

 or spores could be found, but a coarse dark 

 and very granular mycelium was seen. A 

 repetition of the inoculation was successful. 

 18. BANANA inoculated with Guava 

 Gloeosporium. Took rather slowly. On 



Fig. 21. Gloeosporium spores, 

 obtained by inoculating a 

 banana with Gloeosporium 

 spores found growing natur- 

 ally on the guava. 



X 4-00 



the eleventh day the spot was 4 milli- 

 metres' across, and bore a single pustule, 



that the vacuole was more distinct. Two 

 days later other pustules began to appear. 

 On the sixteenth day there were some 

 half dozen well-developed cushion-like 

 pustules, and on the eighteenth day these 

 had increased to a score. The spores were 

 drawn, and appear at Fig. 21. 



19. GUAVA of the large yellow sort was 

 inoculated from a quince that had received 

 its seed from a Gloeosporium found growing 

 naturally on the small red variety of 

 guava. The object of the inoculation was 

 to see if the change of form noted on the 

 quince would be retained on the guava, or 

 w r hether there would be a reversion to the 

 form as it originally occurred on the guava. 



The disease took slowly, but twenty-four 

 days later there were well-developed pus- 

 tules for a distance of five millimetres from 

 the point of inoculation. The pustules were 

 of rank growth, and were in all respects like 

 those from which the seed had been taken 

 on the original small red guava. The yellow 

 guava was ultimately completely destroyed 

 by Penicillium, and this may account for the 

 somewhat slow growth of the Gloeosporium, 

 but it is to be remarked that this yellow 

 guava was a hard specimen and far from 

 ripe to begin with. The spores, on being 

 compared with the drawings made from the 

 original "seed " as found growing in nature 

 on the small red guava, proved to be 

 identical in size, structure, and colour. 



20. APPLE inoculated in two places with 

 Gloeosporium growing naturally on quince. 

 After twelve days this apple was com- 

 pletely brown, soft and rotten, and 

 numerous blackish pustules had appeared 

 and were evidently concentric in arrange- 

 ment with the two inoculated spots. The 

 pustules were not, however, in rings. A 

 few had already sent out "tendrils" of 

 spores. These were mounted and examined, 

 and were found to be rather more spindle- 

 shaped than is common in Gloeosporium, 

 of a greenish colour, rather more finely and 

 densely granular than is usual in the genus, 



Fig. 22. Gloeosporium growing natur- 

 ally on the quince. Compare these 

 original spores with their progeny, 

 shown in the two following illustra- 

 tions. It will be seen that on the 

 apple the spores have become more 

 slender and more pointed. The 

 difference is less marked than in 

 similar cases on pages 16 and 17. 



X400 



Fig. 23. Spores of the 

 Gloeosporium, ob- 

 tained from an inocu- 

 lation on apple from 

 the spores of a Gloeo- 

 sporium found grow- 

 ing naturally on the 

 quince, and shown in 

 Fig. 22. 



which, on examination, proved to be an 

 immature Gloeosporium pustule. The only 

 spore seen was curved, but otherwise had 

 the appearance of the spores sown except 



X400 



Fig. 24. Spores of the Gloeo- 

 sporium, obtained by inocu- 

 lating an apple with spores of 

 a Gloeosporium found growing 

 naturally on the quince, and 

 shown in Fig. 22. Theee spores 

 are from the same inoculation 

 as Fig. 23, but at an earlier si aare. 

 It will be noted that at a later 

 stage the spores became much 

 more elongated. 



and with no central 

 Figs. 23 and 24.) 



clear space. (See 



