440 THE COTTAGE GARDENER AND COUNTRY GENTLEMAN’S COMPANION.— September 1G. 1656. 
the articulations were transformer! were not precisely of 
the same nature as the sporangia, but exhibiting, inde- 
! pendently of the mere couidia of the Oidium, a second 
i form of fruit, as in many other fungi. On the 5th of Sep- 
' teinber of the following year (1852), a paper was read 
| before the Royal Academy of Georgofili of Florence by 
Professor Amici, in which he reports the discovery of bodies 
in the Grape mildew, of precisely the same nature and 
I. mode of production as those in Dr. Plomley’s figure. It 
i will be found from Prof. Amici’s memoir, that he does not 
allow the above mentioned connection between the Erysiphe 
and OUlium, nor indeed, at present, have true ascigerous 
j sporangia been detected in the Grape mildew. These 
' bodies were not, however, found merely in the Grape Oidium. 
j Prof. Amici informs us in his memoir, that they had 
occurred in the mildew of Convolvulus urvensis accompanying 
j an Erysiphe; and I have lately received a very kind letter, 
j in which he sends specimens of Oidia bearing transformed 
cells, not only in the Vine and Convolvulus, but also on the 
common Gourd, the Hop, PI ant ago major, and Trifolium 
pratense (Fig. 3). 11c also found thorn on Artemisia cam- 
pcslris, but I have seen no specimen. Dr. Plomley has 
detected them abundantly in the Oidium of the Rose. I 
bad, indeed, previously seen specimens of the transformed 
joints in the Vine mildew, for Cesati’s Ampelomyces quisquulis, 
liabenhorst, n. 1000, b. published in 1852, is undoubtedly 
the same tiling, though the bodies contained in the cells 
are rather smaller than in Amici’s specimens (Fig. 4). 
This, however, is not the only name which has been im¬ 
posed upon these bodies, as though it were still the fate of 
fungi to have generic importance ascribed not only to their 
mycelia, but even to their separate organs; for Ehrenberg, 
who received his specimens from Amici himself, gave them 
the name of Circinobolus Jlorcntinus; and Riess in Hedwigia, 
1853, p. 23, tab. III. fig. 2, d, e, f. has given to similar 
bodies in Erysiphe lamprocarpa, the name of Byssocystis 
textilis. 
In the early.part of 1853, Ttdasne published in the 
Botanische Zeilnng some admirable observations on the 
genus, without, however, having had the advantage of 
seeing any of Amici’s specimens or those published by 
liabenhorst. His remarks refer principally to two species 
belonging to the genera Uncinula and PhyUactinia, of 
Reveille, in which he found the bodies in question, to which 
be gave the name of pycnidia, as being identical in function 
and essential structure to those which he had before so 
characterised in Lichens (d/cm. p. 108), but differing from 
those observed by Amici, and from all that I have myself 
examined, in resembling exactly the true sporangia, and in 
being furnished with similar appendages. In no single 
instance has this been the case in the species I have had 
the opportunity of observing, and though in some cases the 
bodies were globose, this was not by any means their normal 
form, far the greater part being pointed above. Like M. 
Tulasne, neither myself nor Mr. Broome have ever seen 
I be pycnidia surmounted by a necklace of utricles, but in 
every case rising immediately from the mycelium, very much 
i as represented in the figure in the Hedwigia quoted above, 
i but frequently also from one of the swollen cells of the de¬ 
cumbent mycelium. There is, however, no reason to doubt 
i that such is the case, for the practised eye of Amici could 
I scarcely be deceived ; and Dr. Flomley’s figures, made two | 
j years before those of Amici, and verified by the numerous 
f observations of 1853, are altogether confirmatory of the 
I fact. In one or two instances in Cesati’s specimens (Fig. 
I 4, b.), Mr. Broome found a few delicate threads at the base 
i of one of the pycnidia attached to its walls, but by no 
means emulating those of the sporangia. The bodies con¬ 
tained in the pycnidia do not differ much in size in the 
different species. In the Grape mildew they are (at least 
in Amici’s specimens)* -0004 of an inch long, in that, of the 
Gourd, Plantago major , the Hop, nnd Convolvulus urvensis, 
•0003, and in Trifolium pratense they vary from ’0002 to 
•0004. 
No one has at present seen these bodies germinate, 
unless, indeed, as Amici suspects, they are what Professor 
Pietro Savi “ saw vegetate uuder the microscope, believing 
* In Cesati’a specimen the contents of the pycnidia did not exceed 
•0003 in. 
them to have issued by a regular longitudinal dehiscence 
from the utricles of the moniliform filaments which had 
been supposed to be sporangia.” Now it does not seem 
very probable that Savi could have made.such a mistake, as 
the pycnidia are differently coloured, the colour, indeed, 
often extending down the peduncle; and the observations 
which 1 have now to record resting entirely upon the re¬ 
peated and long-continued examination of Dr. Plomiey, 
confirm what is advanced by the Italian Professor. Both 
in the Hop and l ine mildew be found that the joints of 
the. moniliform threads, though not transformed into 
pycnidia, contained a number of distinct bodies, and not 
merely a granular endochrome. In both cases their number 
appeared to be normally about 300, hut in the Hop mildew 
occasionally they did not exceed 50. In both cases alike 
these bodies germinated very readily when kept moist 
between two slips of glass (Fig. 5), in one instance even 
producing an approach to fertile threads and swellings of 
the articulations, the forerunners, as Dr. Plomley believed, 
of true (Fig. 0) sporangia or pycnidia, it is uncertain which, 
as either may arise front the decumbent threads. But not 
only did they germinate when separated from the utricles 
either by pressure or spontaneous rupture, but even where 
no rupture in the walls of the mother-cell took place they 
germinated in situ, pushing out the shoots of mycelium 
through the walls. In many instances, little germs were 
produced from the cells, which call to remembrance the oh- j 
servations which Tulasne has made on the germinating 
threads of Pnccinia (Fig. 7), though it perhaps may not be i 
certain that they are of precisely the same relative im¬ 
portance. In many eases the fallen utricles adhered 
together in considerable masses, germinating and producing 
an inextricable plexus of spores, myceloid threads, &c., 
and so giving rise to the curdy appearance which is often 
observable in Hop mildew, and, indeed, in most allied forms 
of mildew. These facts are very curious, for the utricles 
themselves have often been observed in a state of germi¬ 
nation, ns figured by Amici and by Dr. Plomley himself in the 
Grape mildew, but in these lower productions, wherever a 
complete cell is produced perfectly individualised, there 
seems a power of reproduction, and we know not how far the 
notion of Turpin may be verified, that it may some day be 
possible to raise a Phsenogsm from a single cell. Whether 
this may lie true or not practically, some cases of grafting, 
as the, well-known one of the so called Scarlet Laburnum, 
tend to show that it is so theoretically. It. will not be super¬ 
fluous to notice further, that in the Hop mildew Mr. 
Broome lias found on the same mycelium as the Erysiphe, 
but on the upper surface of the leaves only, a little brown 
Sphicria (Fig. 8),intermediate in size between the sporangia 
and pycnidia. The perithecia contained perfect uniseptate 
sporidia ‘0005 inch in length, whereas the sporidia of the 
accompanying Erysiphe were about ’0013. It is singular 
that a parasite so closely resembling the Erysiphe in form 
and colour, not to mention other points, should exist in 
such a situation. 
Are we, then, after the facts detailed above and elsewhere, 
to conclude that these Oidia are really states of so many 
species of Erysiphe ? This question seems to me to admit | 
only of one answer, and that affirmative ; for though it may 
he very true that one cannot see the sporangia utricles and 
j pycnidia upon one and the same thread, and it is impossible 
to prove the case by reproduction from the spores, as in that 
of dioecious plants, the body of evidence seems so strong 
and closely connected as to be irresistible. It is true that 
the real sporangia of the Vine mildew have not yet been 
observed, but considering the identity of their pycnidia with 
those of known species of Erysiphe, it seems very difficult 
to suppose that they are essentially diii'erent. The mildew 
of the Peach may ho observed for years without finding 
sporangia, except at a very late period on the branches ; 
and that of the Rose, and of Lycinm barbarnm, as noticed 
by Tulasne, frequently do not proceed beyond the mucoroid 
condition. AVe do not doubt, therefore, that at some future 
period the true sporangia may be found, and we trust that 
the little parasite which has been of such unlooked-for im¬ 
portance may still preserve the specific name originally 
assigned to it, in honour of the very meritorious cultivator 
who first observed it, and did not cease to study its habits 
till he had discovered the proper remedy. It may still, 
