282 GLANDULAR HAIRS. [Chap. XV. 



including na usual some granular matter. These stripes were 

 then immersed in the same solution as before (one part of the car- 

 bonate to 109 of water), and in a few minutes granular matter ap- 

 peared in the lower cells of all the pedicels. The action invariably 

 commenced (for I tried the experiment repeatedly) in the lowest 

 cells, and therefore close to the torn surface, and then gradually 

 travelled up the hairs until it reached the glands, in a reversed di- 

 rection to what occurs in uninjured specimens. The glands then 

 became discoloured, and the previously contained granular matter 

 was aggregated into larger masses. Two short bits of a flower- 

 stem were also left for 2 hrs. 40 m. in a weaker solution of one 

 part of the carbonate to 218 of water; and in both specimens the 

 pedicels of the hairs near the cut ends now contained much granu- 

 lar matter; and the glands were completely discoloured. 



Lastly, bits of meat were placed on some glands; these were 

 examined after 23 hrs., as were others, which had apparently not 

 long before caught minute flies; but they did not present any 

 difference from the glands of other hairs. Perhaps there may not 

 have been time enough for absorption. I think so, as some glands, 

 on which dead flies had evidently long lain, were of a pale dirty 

 purple colour or even almost colourless, and the granular matter 

 within them presented an unusual and somewhat peculiar appear- 

 ance. That these glands had absorbed animal matter from the 

 flies, probably by exosmose into the viscid secretion, we may infer, 

 not only from their changed colour, but because, when placed in a 

 solution of carbonate of ammonia, some of the cells in their pe<licels 

 become filled with granular matter; whereas the cells of other 

 liairs, which had not caught flies, after being treated with the 

 same solution for the same length of time, contained only a small 

 quantity of granular matter. 15ut more evidence is necessary be- 

 fore we fully admit that the glands of this saxifrage can absorb, 

 even with ample time allowed, animal matter from the minute in- 

 sects which they occasionally and accidentally capture. 



SoTifraga rotund i folia (?). The hairs on the flower-stems of 

 this species are longer than those just described, and bear pale 

 brown glands. Many were examined, and the cells of the pedicels 

 were quite transparent. A bent stem was immersed for 30 m. in 

 a solution of one part of carbonate of ammonia to 100 of water, 

 and two or three of the uppermost cells in the pedicels now con- 

 tained granular or aggregated matter; the glands having become 

 of a bright yellowish-green. The glands of this species therefore 

 absorb the oarbtjnate much more quickly than do those of 8axi- 

 fraffd vtubrom, and the upper cells of the pedicels are likewise af- 

 fected much more quickly. Pieces of the stem were cut off and 

 immersed in the same solution; and now the process of aggregation 

 travelled up the hairs in a reversed direction; the cells close 

 to the cut surfaces being first afTecte<l. 



Primula sinensis. The flower-stems, the upper and lower sur- 

 faces of the leaves and their footstalks, are all clothed with a mul- 

 titude of longer and shorter hairs. The pedicels of the longer hairs 

 are divided by transverse partitions into eight or nine cells. The 



