the endosperm (e), and in the liealthy one the gluten layer (Fig. 14 ^)lies 

 between the two tissues. 



Investigations of such grains in the "imported" seed show a similar 

 condition. The seeds seem malformed and the fact that the malforma- 

 tion manifests itself in the position of the embryo as well as in the develop- 

 ment of the endosperm and especially in the thickened growth of the seed 

 coat proves that this malformation must have been completed when the 

 grain was forming in the head. Fertilization has nevertheless taken place 

 normally since the embryo displays leaves and growing point as well as roots 

 (the latter in increased numbers). But some local stimulus must at once 

 have incited a cell increase in the fruit tissue and thereby displaced the em- 

 bryo from the side towards the middle of the endosperm. This stimulus 

 was active during the whole development of the seed and increased the vege- 

 tative activity so that the character of the endosperm underwent a change, 

 for the vascular bundles are those of a vegetative axis. We observe a most 

 important numerical increase of the cells in the tips of the seed, assuming 

 the character of a vegetative axis and, by means of the entangled vascular 

 bundles, resembling a stalk node. Abundant roots develop at these stalk 

 nodes and it is not improbable that leaf buds might have begun had there 

 been a greater aeration of the soil layers. We would then have had a case 

 similar to that in dicotyledonous plants when, as has often been observed, 

 vegetative axes develop from their fruit nodes. 



For such processes, however, the seed lay too deep. There was no ac- 

 cessory apparatus for raising the seed to the upper surface of the soil, such 

 as the elongation of the first internode in the seedling. As a result bacterial 

 decomposition followed, due to the lack of oxygen, as was shown by the 

 rancid smell of butyric acid. 



This is the reason for mentioning the present case here. Had it been 

 possible to determine exactly the causative fungus the case w'ould have be- 

 longed under parasitic diseases. As it was impossible to make the my- 

 celium fruit, the case becomes hypothetical as to the nature of the parasite. 

 Only one thing is certain — viz., that the stimulating mycelium did not belong 

 to the black fungi (Cladosporium, etc.). According to Bref eld's latest in- 

 vestigations on the penetration of the smut into the blossoms, it is highly 

 probable that the smut spores, which have entered the blossom, germinate 

 soon after the fertilization of the grain, and by the slow advance of their 

 mycelia have exerted the stimulus on the seed coat. 



3. Greater Horizontal Differences. 



The individual development within the same plant species is influenced 

 by horizontal changes in the place of cultivation from north to south, or east 

 to west, as well as by the vertical elevation of the habitat. ]>. Candolle^ laid 



1 Sur la methode de sommes de temperature appliquee aux phenomenes de 

 v#g6tation. Separatabzug der Bibliotheque universelle de Gen§ve 1875. 



