September 1, 1882,] THE TROPICAL AGRICULTURIST. 



265 



goes oQ until the whole structure assumes the shape of 

 a flask (fig. SO). This outgrowth of the apex is the first 

 indication of germination, and the free, straight, neck- 

 like portion is the promycelium. The whole process norm- 

 ally (wivauces to completion, while the Teleutospore is 

 still attached to the spore-bearing head, though detached 

 specimens germinate quite readily in water on glass slips. 



When the promycelial tuhe has attained a length of 

 about six to eight times that of the Teleutospore, it be- 

 comes divided by transverse septa into four subequal cells 

 figs. 42 — 45), each of which receives its share of the 

 orange-coloured contents, which have passed along the 

 tube from the spore. In specimens grown on glass slips 

 under cover the promycelium and chambers are much 

 longer (figs. 45, &c.) than those found on the leaves, and 

 the tube may be curved and delicate in the former ca.se, 

 whereas in the latter the promycelium stands up stiff 

 and straight into the moist atmosphere. Tliis may be 

 compared with what occurs with Uredospores germinating 

 on glass and leaves. 



The Promycelium fully formed, each' of the fom- cells 

 (normally) sends forth a slender process, into the cavity 

 of which the coloured contents pass (fig. 45); the process 

 from the upper cell is simply a continuation of its apex ; 

 those from the sides of the lower cells .spring from 

 beneath the septa. The free terminal portion of each 

 of these four outgrowths now swells into the form of 

 a small subglobular conidiian, which receives the remain- 

 ing contents, and at last is simply attached by one point 

 to the constrictetl end of the branch which produced it 

 (figs. 42^46), and may be detached with the greatest 

 ease. 



This conidiian, abstricted in this manner from the pro- 

 mycelium, is much smaller than the Teleittosjwre ; it is 

 usually subglobular, but at times subreniform or ovoid 

 iu shape, aud is filled with the usual orange-red, granular 

 protoplasm (fig. 46), enclosed in a delicate, smooth envelope. 

 Dm'iug the formation of the structures just described — i.e. 

 during the later stages of its germination — the walls of 

 the Teleutospore and promycelium become collapsed (figs. 

 42— 4B, &c.), and, being very transparent, are not easily 

 discovered. 



The Cotiidia germinate readily in water (and, indeed, 

 even while attached to the promycelium), and may pro- 

 duce a long delicate tube (fig. 46 d) very rapidly ; as a 

 rule, however, after forming a large central vacuole, the 

 eudospore protrudes slowly (fig. 46 a) as a blunt, thin- 

 walled, finger-like process, which attains a length of some 

 four times the diameter of the conidium, and then shrivels 

 up and dies. This very simple and transient germination 

 is all I have been able to induce, either on glass or 

 living leaves. 



The pi-oduction of " Teleutospores, &c., appears to be 

 the last act of the mycelium within the leaf, and the 

 brown, shrivelled rema ins of the '* disease patch " soon 

 becomes the prey of Uacteria, &c., which follow in the 

 tracts of such parasites as Hemileia. 



The foregoing description will naturally provoke the 

 in<iiiiry, to what group of fungi does Hemileia belong? 

 ■Without insisting upon an answer to this question, I 

 think it may be worth while to review some of the 

 points in this connection. The general similarity of the 

 " disease-spot " itself to the spots produced by m.iny 

 Urediitetp is .somewhat striking, and the occurence of the 

 orange-red pigment in all the spore-structures, &o., vividly 

 recalls the aume. The mj'celium, ramifying in the lacuna 

 and forming tufted groups here and there externally; 

 the septa, sometimes separatetl by long intervals, some- 

 times more clo.'ely arranged; and again, the centrifugal 

 spread of the fungus, are all points of analogy worth 

 recording. 



It seems impossible to overlook the resemblances of 

 the two spores of Hemileia to the Uralo.ipares and 

 TdctUmpores of an ordinary TJredine. In size, colour, 

 ornament;', lion of the cxospore, mode of germination, and 

 entry of the germinal tube through the stoma after 

 forming a vesicular swelling over its orifice, we have 

 strong analogies, so far as the papillate spore is concerned. 



The smooth, tm-uip-shaped spore, in its mode and time 



of origin, shape, structure and colour, and especially in 



its germination, so strongly recalls the Vredinea, that I 



veutuieit to use the well known name Teleutospore. Indeed, 



34 



the promycelium, with its four cells and conidia, might 

 almost pass for that of Uromyces for mstance. 



Nevertheless, there are sonie difficulties in referring 

 Hemileia to the ordinary Uredines. The curious spore- 

 bearing head which protrudes through the stoma, and 

 the long-necked haustoria, so numerous on the mycelium, 

 are perhaps the chief. How much weight these difficulties 

 carry m.ay be an open question. In cases where two 

 spore-bearing heads have passed tlurough two closely ad- 

 jacent stomata, it rarely occurs that the one or two in- 

 tervening cells have become destroyed; the two heads 

 here become one common, broad, and irregular receptacle, 

 aud very like an ordinary uredinous patch. 



In conclusion, it appears necessary to make a few re- 

 marks on the other forms of fungi, believed by Messrs. 

 Abbay and Morris to be phases iu the life-history of 

 Hernileia vastatyix. It is unpos.sible to explain aU the 

 points raised without numerous drawings, for which there 

 is not room here; at a future date I hope to illustrate 

 more fully the following brief statements. 



The forms figured by Abbay* are very common in 

 germination experiments out here. I recognised them at 

 an early date, cultivated them for' several mouths, and 

 through several generations; they produce mycelia and 

 forms of fructification and spores, &c., which have no- 

 thing to do with Hemileia. Their connection with the 

 spores of the latter fungus is not genetic. So with the 

 forms illustrated by Morris ; t they belong to saprophytic 

 or epiphyllous forms, and can in no way be genetically 

 connected with Hemileia. Of course in such statements 

 I am not resting on the negative evidence that no con- 

 nection has been traced, but upon the results of actual 

 cultivation of these forms, as well as the successful pro- 

 pagation of Hemileia itself as above described. 



May 1st, 1881. 



BuFFAio HoEN Manuee. — The invigorating and sustain- 

 ing properties of horn shavings as a manure is being 

 forcibly illustrated at Ohiswick in :,the case of zonal I'elar- 

 goniums and tuberou.s-rooted Begonias in pots. The wonder- 

 ful wealth of foliage allied to a sturdy growth seen in 

 the plants, and the splendid trusses of flower seen on the 

 Pelargoniums are correct mdications of the value of the 

 manure. Chrysanthemums grown in soil with which the 

 horn shavings have been mixed grow \-igorously, and retain 

 their foliage to the last. The pity is, that the high price 

 charged for it makes its general us too expensive to plant 

 growers. If the price could l)e cheapened, the vendors 

 would do a larger and doubtless eiiually remunerative trade. 

 It should be used only with quick-growing succulent plants ; 

 or, at least, with great care in the case of slower growing 

 subjects. Its value is probably mainly due to the ammonia 

 it contains. — Gardeners^ Chronicle. 



London Tea Ouahges. — The Froduce Markets' Review is 

 very properly heading a crusade against the excessive 

 charges to which importers are liable on tea at the various 

 docks in Londdn. It is shown from a table prepared that 

 the gross charge per chest is 2s. Gd., but this is not all. 

 The unnecessary formahties insisted on, mean vexation and 

 loss of valuable time. The imports of tea into England 

 last year were 94,000 tons, and the Hevicw says that if 

 the importers had paid the same rate upon tea as is paid 

 on coffee, they would have saved a sum of £100,000, or 

 about two-thirds of ^^■hat they now pay. It seems truly 

 monstrous that tea should be thus handicapped at home 

 as against coffee. We fancy few will disagree with the 

 following sensible remarks : — In the abstract, there is not 

 the slighcst reason why tea should pay more than coffee. 

 No doubt the former is more perishable, but then it is 

 packed in wood and lead, and is thus very fully protected. 

 Nor will the ad valorem test explain matters, for the average 

 value of China tea, at any rate, does not now exceed the 

 co.st of coffee. Tea, also, is often opened for inspection, 

 but, on the other hand, all coffee is turned out of the 

 packages, bulked, and repacked. Coffee and tea alike are 

 sold at landing weights and numbers, and there is no 

 special difference between the weight of a bag of coffee 

 aud of a chest of tea. — Indian Tea Gazette. 



» Loc. cit., PI. 14, figsriO toTa ■ 



t ' Quart. Journ. Mic. Sci.,' April, 1S80, Plates X, XI, 

 XIII, and XIV. 



