EDIBLE FUNGI. — THE TRUFFLE. 



255 



them should be kept in a uniform degree of 

 moisture, for, if deprived of this, they soon 

 wither away. On the other hand, if subjected 

 to too great a degree of humidity, mould and 

 other parasitic plants establish themselves on 

 the surface of the tubers, and by degrees ob- 

 struct the absorbing vessels, causing putrefac- 

 tion to ensue, and its concomitant attendants, 

 insects, which prey upon the tubers, and ulti- 

 mately destroy them altogether. The first em- 

 bryo of the truffle is exceedingly small and 

 tender, as is the case with all fungi ; and at that 

 stage it is susceptible of injury, both from excess 

 of drought and moisture. Their form is regu- 

 lated much by the openness or looseness of the 

 soil around them, and hence the necessity of the 

 preparations by deep-trenching and sifting, as 

 above alluded to. " If the soil is everywhere 

 equally loose, the truffle assumes a globular 

 form ; but this is changed if there is on one side 

 a greater opposition than on the other : hence the 

 different forms of the tuber may be explained." 

 As a rule in regard to their artificial cultivation, 

 in connection with the state of the beds, we 

 may, in quoting from the translation of Alex, 

 von Bornholz's treatise, observe, " Where the 

 soil is most moist, whether above or below 

 the truffle, there it will either rise up or sink 

 deeper. The degree of power of attraction 

 of the moisture in the earth to that in the 

 truffle, necessitates such a change of place. In 

 moist summers and in wet winters we find the 

 truffles near the surface, even projecting above 

 it. In dry summers, upon poor dry places in 

 woods, they have often to be dug from a depth 

 of more than half a foot. Here is imposed upon 

 them a greater pressure of superincumbent soil. 

 If the earth is not very light, they cannot be 

 fully developed, and therefore remain small. 

 The largest are, consequently, in general, found 

 not deep under the earth, and in shaded light 

 soil — that is, somewhat moist; they are not, 

 however, so well tasted as those of middling 

 size. Vegetable mould from oak leaves and de- 

 cayed oak appears to contribute to the produc- 

 tion and growth of truffles, as advantageously as 

 the dung of horses does to that of mush- 

 rooms. In the one case, a peculiar animal 

 matter produces the effect ; in the other, a pe- 

 culiar vegetable matter. Perhaps the tannin, 

 or some other yet undiscovered product of the 

 oak tree, may be the principal cause. The more 

 of this matter any species of tree contains, with 

 the greater facility are truffles produced in its 

 vicinity, and in greater numbers." In the for- 

 mation of truffle beds, it would appear that they 

 should be of considerable depth, say from 18 

 inches to 3 feet ; the soil finely sifted, and com- 

 posed of vegetable mould of oak-tree leaves, de- 

 cayed oak sawdust, or probably half-decayed 

 tanners' bark, as each contains traces of the 

 tannin principle. Calcareous or ferruginous 

 earth should be also employed; and the tem- 

 perature, shade, and darkness of an ordinary 

 mushroom-house form the fitting situation. In 



regard to soil, Bornbolz observes, that the 

 greatest number of truffles, and the finest, are 

 found in a light ferruginous calcareous soil. 

 Such a one must, therefore, also be given to 

 the plantations or beds. The soil is found 

 naturally only in particular situations, for 

 which reason truffles do not grow everywhere. 

 The spawn of truffles appears to be extremely 

 delicate, and almost incapable, at least in its na- 

 tural state, of being transported to any great 

 distance ; but this might be overcome, if those 

 in whose vicinity truffles abound were to collect 

 it and form it into spawn-bricks like that of 

 mushrooms. Bornholz, in his treatise, confines 

 himself entirely to their cultivation in woods 

 and forests ; all, therefore, that we can glean 

 from his curious production is the medium suit- 

 able to the production and growth of this fungus 

 in little other than a natural state. 



From the review of Dr Tulasne's " History 

 and Monograph of Truffles," in the " Gardeners 

 Chronicle," 1852, p. 519, we learn that truffles 

 and allied fungi are widely distributed over the 

 globe. Some extend as far north as Upsal, while 

 others are found to occur in Australia. " The 

 black esculent truffles are by nature gregarious : 

 they are found every year in the same spots. 

 They occur exclusively in calcareous or calca- 

 reous and argillaceous soils, both on plains and 

 declivities, and generally on ground more or less 

 shaded by trees, but, as it appears, never on 

 ground planted exclusively with conifers. Much 

 has been written on the cultivation of truffles ; 

 but, at present, experiments made in confirma- 

 tion of published statements have not been at- 

 tended with success. The only fact which is 

 certain is, that their production can easily be 

 effected in certain calcareous soils, even where 

 they may not have been observed before. The 

 plan consists simply in sowing acorns on the 

 soil, and when the oaks have attained the age 

 of ten or twelve years, truffles begin to appear. 

 The extensive truffle layers of Loudon at Vienna 

 were actually produced in this manner. They 

 consisted a few years since of naked uncultivated 

 plains, where truffles were unknown. The plan- 

 tations must not be too thick. They are cut 

 down for the first time when they are about 

 twelve years' growth, and then at intervals of 

 from seven to nine years. They continue fer- 

 tile for about twenty-five or thirty years, when 

 at length scarcely any truffles are produced. 

 From the facility with which the mycelium, or 

 spawn, is developed in specimens which have 

 been brought from a distance, Dr Tulasne con- 

 ceives that it might not be impossible to trans- 

 plant the more valuable species into truffle layers 

 where the more common sorts only occur. Their 

 presence appears in general to depend more on 

 the mineralogical character of the soil than on 

 particular temperature, limestone districts being 

 certainly most favourable to their growth." 



The European names are — Truffel in German ; 

 Tartufo nero in Italian; Truffe in French; and 

 Aardnoot in Dutch. 



