of a Hybrid Digitalis. 263 



Flowers of lutea are not unfrequent with the lower lip notched 

 (Fig. 7), which indicates the presence of a supernumerary petal 

 blended into the tube of the corolla. In about half a dozen 

 instances I even found this petal quite free, (Fig - . /3) and I be- 

 lieve occupying the same position as the sixth sepal in the 

 anomalous cases just referred to. In D. ferruginea, however, I 

 have sometimes found a sixth sepal and a notched lip in the 

 same flower. These anomalies may therefore be considered ana- 

 logous phenomena among the supernumerary developments of 

 the two organs. 



3. Pollen. In comparing the action of the three pollens when 

 immersed in water, I observed all the phenomena visually at- 

 tendant on this experiment, to take place in those of purpurea and 

 lutea: their grains quickly swelled and their granules were ex- 

 ploded in the form of a dense cloud (Fig. F and £). Two kinds 

 of granules were also observed, the smallest and most numerous 

 of which were too minute for me to be able to ascertain their 

 precise shape and dimensions by the highest powers of my in- 

 struments; the others, much fewer in number, were considerably 

 larger, and lay dispersed among the smaller like pellucid spots 

 on a darker ground ; and these might even be distinguished 

 through the coats of the grains before their expulsion had taken 

 place. Some pollen of purpurea taken from a withering stigma 

 exhibited very distinctly the presence of the exserted mem- 

 branous tubes (boyaux) described by A. Brogniart, Amici, and 

 others, in the Ann. des Sciences, (Fig. G). Some of the granules 

 also were marked on the surface by three blotches (Fig. H). 

 Grains of pollen taken from the hybrid readily swelled upon 

 immersion in water, though most of them appeared to he void 

 of granules. Some few however certainly contained the larger 



