HARDWICKE'S SCIENCE-GOSSIP. 



199 



germinate and produce small transparent spores 

 (promycelium spores) that are readily carried about 

 by the wind. The puccinia spore germinates by pro- 

 truding from each of its segments a single short 

 germ-tube (the promycelium), which gives off near 

 its extremity about three tapering branches, each of 

 which bears a single promycelium spore. ^Vhen 

 these promycelium spores fall upon the leaf of their 

 proper host-plant, they in their turn germinate, but 

 their germ-tubes are very diminutive structures as 

 compared with those of the aecidium and uredo spores. 

 They do not search for the stomata, but bore their way 

 straight through the cuticle of the leaf at the place 

 upon which they fall. The mycelium thus produced 

 in due time (from eight to twenty days) produces the 

 recidium with which we began. Thus the cycle of 

 the puccinia is completed, and a very interesting 

 ^tudy is the life history of a puccinia, and one which 

 can be with care and patience easily observed by the 

 nncroscopist. 



In some species the secidium has not yet been dis- 

 covered, as P. anindiiiacea on reed. There are two 

 puccinire on the common reed which have been 

 known for many years ; one, the above mentioned 

 that is instantly recognised by the verj' long stalks 

 upon which its teleutospores are borne. The other 

 has heretofore in this country been set down as a 

 variety of /'. gi-atm'iiis. It is however a distinct and 

 good species. The teleutospores very closely resemble 

 those of P. grai/iiiiis, but the uredo is quite distinct ; 

 its spores are of a different shape and are brown, while 

 those of P. gramiiiis are orange. But there is another 

 important difference. The uredo of the species in 

 question is provided with a number of bodies called 

 paraphyses, which are not present in the uredo of 

 P. graininis. This spring, my friend Mr. Thomas 

 Brittain, of Manchester, paid me a visit, and incident- 

 ally mentioned his inability to find yEcidiuin riiinicis 

 upon dock, for which he had searched many years. 

 We were driving along a country road at the time, 

 and I remarked that if he looked for it upon the docks 

 growing near the first lot of reeds we came to he 

 would most likely find it. We accordingly pulled up 

 at the next place where reeds were growing that we 

 came to, and, sure enough, upon the only dock grow- 

 ing there was the secidium my friend was in search 

 of. I also showed him the same secidium in my 

 garden which I had produced by causing the promy- 

 celium spores of Puccinia magniisiana to germinate 

 upon Kumex Iiydrolapatliuni. It will be within the 

 knowledge of those of your readers who have searched 

 successfully for ^cidiiim rumicis that when they have 

 found it, it has been near Phragniitis communis. Of 

 course stray promycelium spores may be blown to an 

 almost indefinite distance, but to find the recidium in 

 plenty, you must search near reeds upon which Piicci- 

 itia iitagiiusiaua grew the previous year. Of course 

 there may be reeds without this puccinia, but if my 

 memory serves me, Mr. Brittain said that the reed 



was not a common plant in his district. It should be 

 remembered that the spores of the secidium in ques- 

 tion falling upon dock leaves will not reproduce the 

 aicidium ; this can only originate from the promy- 

 celium spores of Piiccitiia magnusiana, and it is 

 equally true that the jEcidiiirn bcrberidis only arises 

 when the promycelium spores of Puccinia graminis 

 have gained entrance into a barberry leaf. 



The accompanying figures' which have been drawn 

 from nature show the various points that have been 

 alluded to — the structure of an aecidium cup, and 

 the manner in which the spores are formed, their 

 mode of germination and entrance into the stomata 

 of the host-plant ; the uredo spores and its germina- 

 tion and mode of entrance, the teleutospores Puccinia 

 graminis, magnusiana and ariindinacea ; the ger- 

 mination of the teleutospore, and the promycelium 

 spores both of hetercecismal and antoQ:cismal species 

 piercing the cuticular cells of their host-plants. 



It is in the hope that these few remarks may 

 augment the interest already taken by many micro- 

 scopists on the subject of micro-fungi, that they have 

 been written, especially as in this country the mor- 

 phological aspects of these organisms have not 

 received the attention they deserve. 



Charles B. Plowright. 



King's Lynn. 



THE LOESS. 



THERE is a deposit, yclept the Loess, 

 That's puzzled the brains of the savants I 

 guess, 

 It's found in the vale, and a-top of the hill, 

 'Tis scarcely a clay, and it is not a Till ; 

 No gravelly bed do its sections unfold. 

 Nor boulder subangular, flattened or rolled ; 

 Strange and unstratified, made to distress, 

 Is this great deposit we call the Loess. 



Would you make its acquaintance, unwilling to lag 



Behindhand in knowledge? consult Geo. Mag., 



Where Howarth has marshalled his facts in a train, 



This "rummy" deposit for once to explain, 



By one great debacle tremenjus of floods ! 



That tore up the soils, and stirred up the muds, 



Making and mixing a liquefied mess, 



Which settled and dried, and became the Loess. 



Bold Baron Richthofen now stalks on the scene, 

 To polish off Howarth, so fresh and so green ; 

 The steppes of Mongolia resound to his wain. 

 And he kicks up a whirlwind of dust in his train. 

 Which settles on all things, to prove, if you please, 

 The agent of change is the air and the breeze ; 

 'Tis a dusty deposit, no more and no less, 

 A windy formation this funny Loess ! 



Should it prove due to the flood or the gale, 

 Or the Champions dusty or muddy prevail, 



