422 BACTERIA OF THE SPUTA 



wards go round the optical axis, or substituting for it the dark 

 diaphragm, pushed on one side, and making the stage rotate with 

 the upper part of the instrument round the same axis. In the 

 latter case, a better effect is obtained when the ear is horizontally 

 disposed and is sti-uck from behind by the pencil of light, almost 

 parallel with the stalk, beginning from the root, so that the 

 luminous rays run along its axis. Then, focussing, the general 

 effect of the six series of spores becomes striking, the whole ear 

 takes a beautiful mulberry appearance, of which it is impossible 

 to give a satisfactory representation. 



The figures which we have drawn are, however, sufficient to 

 give a proper idea of the peduncles in question. In Fig. 23, «, we 

 have represented a short and young ear, as seen stained with the 

 acidulated solution of iodine, magnified to 1,700 diameters; in it 

 the spores are thin, and its clustered form is most striking, as we 

 can even perceive posterior rows of little spores. In c (same 

 figure) is seen an older ear, thicker and longer (same staining, 

 and magnified 1,170 diameters) in which, however, the peduncles 

 are sufficiently distinct. In d^ then (same staining and magnifica- 

 tion), is drawn a short fragment of a fertile stalk, found by chance 

 in one of the numerous preparations ; only two spores are seen at 

 its base, and higher up the peduncles still thick, but without 

 spores ; the rest of the ear is wanting."^' In the above Fig. 24 

 (weakly stained with gentian violet, magnified to 3,100 diameters) 

 the spores are intact, their funnel-shaped peduncles are visible 

 through the viscid substance, moderately stained. The stalk 

 exhibits several gemmules of reserve. 



The facts hitherto given (in support of the arguments 

 expounded or simply suggested in the preceding Memoir), which 

 everybody can verify for himself, are, in our opinion, sufficiently 

 conclusive to warrant us in affirming the existence of a really 

 external sporification or fructification of the normal parasite of the 

 mouth upon six longitudinal series of peduncles and spores. But 

 for a more evident proof, take the specimen drawn in Fig. 25. 

 This specimen, obtained by pure chance, amongst the number- 

 less preparations examined, represents a stalk which, emerging 



* The attenuated appearance of this stalk probably depended upon a flowing- 

 out of its sap or germinal matter owing to rupture. 



