MICROSCOPIC STRUCTURE OF PHANEROGAMIC PLANTS. 



387 



surface) retain their original transparence, being marked only with an 

 indication of spiral deposit in their interior. In the seed of Dictyoloma 

 Peruviana, besides the principal f wing ' prolonged from the edge of 

 the seed-coat, there is a series of successively smaller wings, whose mar- 

 gins form concentric rings over either surface of the seed; and all these 

 ivings are formed of radiating fibres only, composed, as in the preceding 

 case, of the thickened walls of adjacent cells; the intervening membrane, 

 originally formed by the front and back walls of these cells, having dis- 

 .appeared, apparently in consequence of being unsupported by any second- 

 ary deposit. 1 Several other seeds, as those of Sphenogyne speciosa and 

 Lopliospermum erubescens, possess wing-like appendages; but the most 

 remarkable development of these organs is said by Mr. Quekett to exist 

 in a seed of Calosanthes Indica, an East Indian plant, in which the wing 

 extends more than an inch on either side of the seed. Some seeds are 

 distinguished by a peculiarity of form, which although readily discernible 

 by the naked eye, becomes much more striking when they are viewed 

 under a very low magnifying power: this is the case, for example, with 

 the seeds of the Carrot, whose long radiating processes make it bear, 

 under the Microscope, no trifling resemblance to some kinds of star-fish; 



Seeds, as seen under a low magnifying power: A, Poppy; B, Amaranthus (Prince's feather); 

 Antirrhinum majus (Snap-dragon) ; D, Caryophyllum (Clove-pink) ; E, Bignonia. 



and with those of Cyanthus minor, which bear about the same degree of 

 resemblance to shaving-brushes. In addition to the preceding, the fol- 

 lowing may be mentioned as seeds easily to be obtained, and as worth 

 mounting for opaque objects: Anagallis, Anethum graveolens, Begonia, 

 Carum carm, Coreopsis tinctoria, Datura, Delphinium, Digitalis, Ela- 

 tine, Erica, Gentiana, Gesnera, Hyoscyamus, Hypericum, Lepidium, 

 LimnocJiaris, Linaria, Lychnis, Mesembryanthemum, Nicotiana, Ori- 

 gamme oniles, Orobanche, Petunia, Reseda, Saxifraga, Scrophularia, 

 Sidum, Sempervivum, Silene, Stellar -ia, Sympliytum asperrimum, and 

 Verbena. The following may be mounted as transparent objects in 

 Canada balsam: Drosera, Hydrangea, Monotropa, Orchis, Parnassia, 



1 See H. B Brady in " Transactions of Microsc. Society," N.S., Vol. ix. (1861), 

 . 65. 



