218 Transactions of (he 



be discerned like spore formation or mycelium growth inside the 

 tissues, though in one case something of the kind occurred out- 

 side. 



On the 15th T'Jarch a very young leaf, 5 — 8" long and 3 — 8" 

 wide, was examined. This leaf was green with a dark centre. The 

 under side was thickly set with the yellow bodies, which were dis- 

 tributed as freely on the green as on the dark part. The cells of 

 the dark part when viewed by reflected light were found on the 

 whole rounder and more prominent than those of the pale green 

 parts. It was also noticed that the yellow bodies were not distri- 

 buted at random, but ranged in something hke a definite pattern 

 with certain intervals between them. All of them were well filled, 

 and nearly, if not quite, sessile. No stalked appearance was distinct 

 in any leaf with the yellow bodies thoroughly filled and looking 

 healthy. 



On the 18th March, two fresh-grown young leaves were taken 

 from another plant, the smallest being about 1 — 8" long. On its 

 under surface the yellow bodies abounded, quite as advanced in 

 development as similar bodies on old leaves of last year's growth. 

 Some of these contained distinct granules not unlike spores, and 

 spore-like bodies were found on parts of the leaf. The healthy 

 bodies were well filled and almost sessile. Dead ones showed the 

 footstalk very plainly. On this leaf there was an appearance of 

 mycelium, but not at all distinct. 



The next observation was made on the 24th, the subject being 

 a young leaf that had grown rapidly, and which was not quite old 

 enough to open completely. This was carefully flattened out in a 

 compressorium, care being taken to avoid injuring it by the pres- 

 sure. Viewed by reflected light this leaf ofiered a most beautiful 

 spectacle. It was full of colouring matter and fluids, and very hairy 

 on its under surface, the hairs being developed more in proportion 

 than the general tissue of the leaf. Amongst these hairs, ghtter- 

 iiig with fluids, some rich violet, and some white, were numbers of 

 the yellow bodies, brimful of their coloured contents, many exhil)it- 

 ing the cross, and many in which it was not noticeable. They 

 were extremely brilliant, of a fine topaz tint and high refractive 

 power. They varied somewhat in size, a good plump one being 

 about 1 — 80U", but some were smaller and some larger. 



It seemed very unlikely that a quickly-grown and newly-opened 

 leaf should have a fungoid parasite developed as well as every old 

 leaf that was examined ; and the regular arrangement of these 

 bodies assisted the idea that they might be glandular structures 

 belonging to the plants in a healthy and natural state. Somewhat 

 similar bodies, but white, were found on the under surface of a leaf 

 of garden sage; Mr. Eeeves showed me others (white) on Mentha 

 viridis, or garden mint ; and unless it can be shown that the 



