BULLETIN OF THE BUSSEY INSTITUTION. 409 
the other hand, the hyphz wind themselves tightly around the stalks 
of the stellate hairs of the olive, from which they cannot be removed. 
If the fungus should attack both oranges and olives, it is very evident 
why the latter would suffer much more than the former. Apart from 
the absence of hairs, which invariably constitute a large proportion 
of the scrapings of the olive-leaves, that from the orange-leaves is pre- 
cisely identical, — the same moniliform hyphz, bearing Macrosporium 
and Helminthosporium spore-like bodies, the same pycnidia and stylo- 
spores. Micrometric measurements only confirm the identity. On 
the orange-leaves sent me, there is a greater proportion of pycnidia, 
and a smaller proportion of stylospores, than in case of the olive- 
leaves; but that is, of course, an accidental difference, as the olive- 
leaves themselves vary. On the orange, the proportion of Helmintho- 
sporium-like spores is much greater than on the olive: but, from the 
facility with which the so-called secondary forms of fruit are produced 
in fungi, and their great variability, that is not a fact of any impor- 
tance ; and we can in the most decided manner affirm that the fungus 
is the same on both plants. 
The first account of a fungus growing upon orange-trees, resembling 
in its habits that received from California, was given by Persoon, 
in his Mycologia Europea, p. 10, published in 1822. His descrip- 
tion of the new fungus is very briefly given in the following words: 
“Fumago Citri, late effusa crassiuscula nigro-grisea. Provenit in Eu- 
ropa meridionali ad folia Citri Medicz, que seepe tota induit.” Later, 
Turpin published an account, with a figure, of a species which he 
also called Fumago Citri, which Montagne made the type of a new 
genus, Capnodium, published in the Annales des Sciences Naturelles, 
3 série, tome 11,1849. Montagne seems to have had doubts as to the 
identity of the Fumago Citri of Persoon with that of Turpin. Al- 
most simultaneously with the publication by Montagne of his genus 
Capnodium, Berkeley and Desmazieres published, in the Journal of 
the Horticultural Society of London, vol. iv. p. 252, an article “On 
some Moulds referred by Authors to Fumago.” In this communica- 
tion, there is the following description of the orange fungus briefly 
referred to by Persoon and Montagne: “ Capnodium Citri, Berk. and 
Desm. Sparsum, setosum ; peridiis elongatis; mycelio ramoso moni- 
liformi pulcherrime reticulato; sporidiis oblongis minutis. Fumago 
Citri, Pers., Myc. Eur., vol. i. p. 10; Turpin 1. c. On leaves of dif- 
ferent species of Citrus. France: Persoon, Léveillé.” 
VOL. I. 52 
