TUB 



TUBERCLE, a fmall, hard, fuperficial tumour, cir- 

 cumfcribed, and permanent, or fuppurating partially. — Bate- 

 man's Synopfis of Cutaneous Difeafes. 



TUBERCULA Quadrigemina, mylnatomy, a part of 

 the brain. Sec Brain. 



TUBERCULARIA, \n Botany, fo called from its fmall 



tubercular figure Tode Fung. Mecklenb. fafc. 1.18. Perf. 



Syn. Fung. iii. Obf. Mycol. fafe. i. 78 Clafs and 



order, Cryptogamm Fungi. Nat. Ord. Fungi. 



Eff. Ch. Roundifb, compaft, fmooth, permanent, foluble 

 in wet. 



i.T.difcoidea. Difcoid Tubercularia. Perf. n. I. Obf. 

 Mycol. n. 138. fafc. i. 79 — Burfting from the cuticle of 

 trees, crowded, even, red ; with a difcoid permanent bafe. — 

 On decayed branches of Maple. 



2. T. ■vulg'dris. Scarlet Tubercularia. Tode 18 — 20. 

 t. 4. f. 30. Perf. n. 2. (Tremella purpurea; Linn. Sp. 

 PI. 1626. H'udf. ^6^. Lichenoides tuberculofum amoen^ 

 purpureum; Dill. Mufc. 127. t. 18. f. 6. ) — Aggregate or 

 icattered, bright red, corrugated, with a thick pale bafe — 

 Very common on dead or dying branches of trees, efpeci- 

 ally currant-bufhes, where it becomes confpicuous by its 

 fcarlet or deep-rofe colour. 



3. T. granulijta. Dull Granulated Tubercularia. Perf. 

 n. 3. — " Roundifti, dull red, with a corrugated granulated 

 furface." — On the branches of Sycamore, or other fpecies 

 of j^cer, but rare. Its colour is brownirti and opaque ; 

 yellowifh within. Perfoon. < 



4. T. conjlums. Confluent Tubercularia. Perf. n. 4 — 

 " Crowded and confluent, of a flefhy red brick-colour, fmall, 

 oblong, angular or flattifli." — On dry branches of the Com- 

 mon Maple. Coloured much like T. intlgivh, but fmaller, 

 and fofter. 



5. T. cajlaneii. Chefnut Tubercularia. Perf. n. 5 — 

 " Scattered, fmall, funk in the bark, flattifh, very fmooth, 

 bright red." — On the bai'k of the chefnut-tree. Half the 

 fize of T. vulgaris, and fcarcely projefting out of the cuticle 

 of the bark. Its colour externally is like that of a ftraw- 

 berry, the infide yellowifh, firm. 



6. T. rojea. Rofy Tubercularia. Perf. n. 6. Obf. 

 Mycol. n. 137. fafc. 1.78. (Lichen rofeus ; Schreb. Lipf. 

 140.) — Scattered, loofe, irregularly globofe, rofe-coloured. 

 — On trees, efpecially adhering to Livhenjiellaris, parietinus. 

 Sec. We have found it on tlie former at Hetherfet, near 

 Norwich. The bright -pink httle mafles, of which this fpe- 

 cies confifts, might be taken for the tubercles of fome Lichen; 

 but they diflblve in wet. 



, TUBERCULUM Annulare, in Anatomy, a part of 

 the brain. See Brain. 



TuBERCULUM Loweri, a fmall eminence in the right au- 

 ricle of the heart. See Heart. 



TUBERNICENSE Oppidum, Tubernoke, in Ancient 

 Geography, a town of Africa, built in form of a crefcent, 

 between the fummits of a mountain, 7 leagues S.W. of 

 Tunis. 



TUBE RNO KI, in Geography, a town of Tunis, anciently 

 the fee of a bifliop ; 2 l miles S.S.E. of Tunis. 



TUBEROSE, in Botany, fee Pouanthes. This Eng- 

 bfli name is not compounded of tube and rofe, as moil people 

 would naturally conceive, but originates in the old appel- 

 lation of Tuberofe, or Tuberous, Hyacinth, Hyacinthus iu- 

 berojus ; alluding to the tuberous root, and the refcmblance 

 of the flower to a Hyacinth. 



TUBEROUS Roots, in Gardening and Agriculture, 

 fuch as confiil of one or more fwelled or knobbed tubers, of a 

 folid flefhy fubftance. In this tribe are comprifed many plants 

 of the ornamental flowery kind, and fome efculents of the 



9 



TUB 



kitchen garden ; as in the former, anemone, ranunculus^ 

 filipendula, many forts of iris, aconitum, paeony, orchis, cy- 

 clamen, winter-aconite, day-lily, &c. ; fome alfo with bulbo- 

 tuberous roots, as gladiolus, polianthes or tuberofe, ophrys, 

 &c. ; and of the efculent tuberous roots are the potatoe and 

 Jerufalem artichoke ; all of which plants are principally per- 

 ennial in their roots, being perpetuated annually by offsets, or 

 cuttings for fets. See Root. 



It has lately been fuggefted, and in fome meafure con- 

 firmed by experiment, that, in cultivation, the root of this' 

 kind, called the potatoe, is hable to have the difeafe termed 

 the curl produced in crops of it, by the tubers which are 

 ufed for feed-ftock or fets having been allowed to become 

 too ripe the preceding year ; and that this praftice of over- 

 ripening, being repeated year after year, is the real caufe of 

 the difeafe, the vegetative power in the tubers being in this 

 way exhaufl;ed. 



It has been long known to all cultivators of this fort of 

 crops, that the ufual method of reproducing any particular 

 variety of the root is by cuts or fets of the tubers ; and that 

 this manner of propagation is continued from year to year,, 

 as long as that particular fort is vviflied for, without ever 

 thinking of reinvigorating the feed-Jloch, or tubers for 

 planting, by raifing new plants from the real feed ; the 

 fpecies being reproduced only by fowing the true feeds of 

 the plant. It is only thus that neto vai-ieties are obtained^ 

 But if feeds be taken from any particular variety which is 

 wifhed to be preferved, and if care be exercifed that the 

 plants fhall have no communication with the farina of any 

 other plants of the fame fpecies in flower, then the produce 

 of thefe feeds will probably be the fame with that variety 

 from which the feeds were faved ; and from the feed-ftock 

 being renewed, and reinvigorated in this manner, it feems 

 hkely that the variety fo obtained may, by obferving a pro- 

 per management, be preferved from this difeafe, or any other 

 kind of degeneracy, for any length of time. 



This opinion of the over-ripening of the feed-ftock for 

 the fupply of the enfuing year, by allowing it to remain too 

 long in the ground, efpecially when planted early, and of the 

 repetition and continuance of it rendering the tubers wholly 

 unfit for producing vigorous healthy plants, by exhaufling 

 their power, being the chief caufe of this difeafe, has however 

 been almoft uniformly objefted to, as being quite contrary to 

 experience in regard to feeds in general, as full ripenefs has 

 been confidered the beft recommendation of them. It is 

 notv/ithftanding apprehended, that this objeftion arifes from 

 the taking of an improper view of the matter. For though 

 it be true, that all of what are properly called feeds are im- 

 proved by being thoroughly ripened ; the cuts or fets taken 

 from the tubers of this fort cannot, ftriftly fpeaking, be con- 

 fidered as feeds. The planting cuts of tliis kind of tuberous 

 root, is analogous, it is fuppofed, to budding or grafting of 

 trees, being only a fecondary mode of propagation, and con- 

 fequently that fuch an objeftion cannot hold good. Befides, 

 the fuggeftion is illuftrated and fupported by different other 

 circumflances and confiderations, as well as by the well-known 

 powerful caufe which weakens the vegetative power in the 

 tubers, — that of allowing the plants that are intended for the 

 fupplying of feed-ftock for the enfuing year to run to flower, 

 and produce feed. This, it is thought, fhould in all cafes 

 be prevented, by cutting off the flowers as they appear in 

 their embryo ftate. In this way, by turning nature from her 

 ordinary courfe, to force her to exert herfelf in another di- 

 reftion, and to throw back into the tubers that portion of 

 the vital principle of the plant, which would have been ex- 

 haufted in the formation of flowers and feeds. Nothing will, 

 it is fuppofed, contribute more to prevent degeneracy m this 



fort 



