346 THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, August 31, 1858. 
A MICROGRAPHIC STUDY OF THE DISEASE OF SAFFRON KNOWN UNDER 
THE NAME OF TACON. By C. Moisttagne, D.M. 
The Saffron Crocus ( Crocus sativus, L.) is a plant known 
at a very early period, and admitted, from the beauty of its 
flowers, as an ornament of our gardens; its economical uses, 
however, and its medical qualities render it still more im¬ 
portant, and altogether worthy of fixing our attention. The 
interest attached to its successful culture has made it a matter 
of duty to study carefully the diseases to which it is subject, ' Leveille, we consider its species as Sclerotia , this singular 
either with a view to their prevention, while there is still an l parasite consists of sclerotioid, almond-shaped tubercles, United 
Academy for 1728,” and has since been figured by Bulliard* 
under the name of Tuber joarasiticum , which Persoon after¬ 
wards changed into Sclerotium crocorum. Decandolle finally 
raised it to the dignity of a genus, and called it Rhizoctonia. 
Whatever name we may retain, whether, with Decandolle and 
Fries, we adopt the genus Rhizoctonia, or, with Desvaux and 
opportunity, or to limit, as much as is in our power, the 
terrible ravages which they commit. 
Amongst these, there are two especially which have long 
excited the attention of cultivators. The first, which is not, 
properly speaking, a pathological affection, though frequently 
productive of death, is due to the presence of a parasitic 
fungus, living at the expense of the plant which it attacks. 
This fungus was classed amongst truffles by Duliamel, who 
gave the first good description of it in the “ Memoirs of the 
SG qa 1?5- S Sa ®' on Disease, from a drawing by M. Montagne. The figures magnified 
JO diameters. 1, healthy cells, of which a is filled with starch ; 2, a diseased 
cell; 3, stratum of compressed cells. 
by bvs3oid filaments going from one to the other, forming a 
sort of subterraneous net. It is by means of these filaments, 
which are attached to the rootlets of the plant, or which 
creep over the surface of the bulbs, after having pierced their 
integuments, that the parasite appropriates their nutritious 
juices after the manner of Cuscutas , and induces, if not direct 
death, at least a weakly development. 
The second disease has received from cultivators of Saffron 
the vulgar name of Tacon , an old French word, borrowed, 
probably, from the Italian Taconne , which signifies in 
either language a piece of leather patched on a shoe-sole. 
Our first knowledge of this pathological affection is due, 
as far as I know, to Fougeroux de Bondaroy, who lias 
described it as follows in the Memoirs of the Academy of 
Sciences at Paris for the year 1782 :— 
“Brown spots are first observed in the tissue of the 
bulb, which injure its substance, and, though the coat 
seems sound, the spots beneath enlarge in proportion as 
the malady increases, the texture is destroyed, the ulcer (for 
so this disease may be termed) gains ground, and consumes 
the flesh until it is changed into a black dust; the coats 
themselves finally change colour, becoming red ; the bulb 
rots, or rather is reduced to a substance resembling vege¬ 
table mould. 
“ The malady increases rapidly; the Tacon is commu¬ 
nicated to neighbouring bulbs ; but for this end they must 
either be in contact, or the dust rest¬ 
ing on them must communicate the 
disease, and this communication is 
effected slowly.This dust is 
different from that which results from 
decay. It has rather appeared to me 
to be of the nature of bunt in wheat.” 
The author then compares bunt with 
the Tacon in respect of propagation:— 
“ In wheat it is the starch-bearing 
part which is corrupted; in the bulb 
also it is the starch which is first de¬ 
stroyed, and the bulb equally with the 
wheat turns into a black foetid powder.” 
From all which it may be inferred 
that the disease which attacks the 
bulbs of Saffron, for the communi¬ 
cation of which I am indebted to M. 
Rayer, is not due to the presence of a 
Rhizoctonia , but is clearly the result 
of that sort of decay which is called 
Tacon. The present state of science 
requiring our investigations not to 
stop at the surface of things, but that 
they should be pursued as far as our 
powers of observation permit us to 
penetrate, it will not be thought su¬ 
perfluous if I add the following details 
to the description of Fougeroux. They 
wull enable us to appreciate correctly 
the mode of change of the tissues 
examined under the compound mi¬ 
croscope, and will complete the very 
imperfect information at present in 
existence on the nature of this affection. 
At the beginning of the malady we 
perceive on the surface of the bulb, if 
we separate slightly the fibres of the 
coat, little orbicular brown spots, of 
the size of a lentil. I believe that the 
point of origin is generally that of the 
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