Brady, on the Seed of Dictyoloma Peruviana. 65 



fections of object-glasses, this result led to a definite opinion 

 as to the quality of the power employed. 



I will only add, that when combined with the hemispherical 

 condenser and the whole series of eye-pieces, the new half-inch 

 is a battery of microscopic powers, and will be a good substi- 

 tute, in case of slender purses, for the To^h, To^h, ith, and 

 other fractions, I may therefore be permitted to congratulate 

 our society on the valuable results consequent upon the 

 attainment of almost unlimited aperture, combined with per- 

 fect flatness of field, in powers as low as the ^ and -poth ; and 

 let it not be forgotten, that English opticians still take the 

 lead in these improvements, which should yield honour as well 

 as profit to themselves. 



On the Seed of Dictyoloma. Peruviana, D.C., &c. 

 By Hy. B. Brady, F.L.S. 



(Read June 12tli, 1861.) 



There are few points of greater interest to the micro- 

 scopist, or that better repay his attention, than the external 

 character of the seeds of plants. Many, from their mere 

 superficial beauty, have become popular show-objects ; but a 

 deeper interest is awakened, and an almost boundless field 

 of investigation is suggested, by such phenomena as those pre- 

 sented by the peculiar spiral cells of the testa of Collomia, 

 Ruellia, or Salvia; the curious hairs from the seeds ofCobaea 

 or Acanthodium ; the beautiful surface markings on those of 

 Papaver, Lychnis, or Silene; the coma of Hoya and other 

 Asclepiads ; or the membranous wings so common amongst 

 the Bignoniacese. That there are many new and valuable 

 facts to be gathered from a systematic study of these 

 structures, no one who has given much attention to them 

 -can doubt, and I only regret that my own observations, 

 though extending over a considerable time, have as yet been 

 too desultory and disconnected to be of much practical 

 value. Recently, however, a specimen was placed in my 

 hands so peculiar in some of its characters that I have 

 thought it might properly form the subject of a short 

 notice. 



The seed of Eccremocarpus scaber, a half-hardy climbing 

 plant, common in our gardens, is familiar to most as a 

 microscopic object ; but as an acquaintance with this will 



