398 Dr. H. Charlton Bastian on the Origin 
within outwards, and the surface of the orange here and 
elsewhere showed no trace of Mould of any kind. 
The companion orange again showed no organisms, either 
internally or externally. 
There is no means of accounting for Mould springing up 
in the interior of an orange by infection from without. Ina 
memoir entitled “‘ Recherches sur la Pourriture des Fruits” *, 
Davaine points out that in fruits, such as the apple, the pear, 
and the medlar, in which there is an open calyx, “le tube 
calicinal peut conduire les spores ou leurs filaments jusqu’au 
centre du fruit. C’est ainsi que se produit le blettisement f, 
qui n’est autre chose qu’une pourriture ”’; but the process of 
rotting, he says, is always external “ chez les fruits qui sont 
partout recouverts d’un épiderme, tels que le citron, orange, 
et les fruits 4 noyau.” 
In the case of the apples to which I have referred, there 
was clearly no such process of infection from within as that 
to which Davaine refers. In the Canadian apples the change 
occurred simultaneously in many points almost as much 
removed from the seed-cavities as from the surface of the 
apples, and a comparison of what was found in the primor- 
dial utricles of the cells with what has been found in similar 
situations in the potatoes that have been referred to, leaves 
little room for doubt that what are shown in Pl. XXVI. fig. 8, 
C, D, are really germs of microorganisms; while in the 
other apple delicate Fungus mycelia (fig. 7, A) were found 
springing up within various isolated cells in the midst of 
the substance of the fruit. Again, the presence of the 
Bacteria and other organisms within the cells of the two 
small turnips and the different potatoes that have been 
referred to are equally incapable of being accounted for by 
any process of infection from without. ‘There is absolutely 
no relation between what I have found in these cases and 
an actual process of infection such as M. C. Potter has 
described (see p. 885). We have to do, in fact, in the cases 
that I have cited, with motionless germs of microorganisms 
arising de novo in or on the substance of the primordial 
utricles of isolated cells, having intact walls, and scattered 
throughout the substance of the potatoes and the turnips in 
question—in all parts, that is, except in the superficial 
* Compt. Rend. 1866, pp. 277-344. 
+ That is, the mellowing process that occurs in pears and medlars 
more especially. Further on in his paper Davaine says he has “ recently 
recognized that this latter process (blettisement) may take place where 
spores are excluded, and in the absence of any mycelium.” 
