982 RECORD OF CURRENT RESEARCHES RELATING TO 



ones being detected farther down upon the raphe. A study of the 

 development of the coma of Epilohium shows that the first indication 

 of it is a tuberculated appearance of the chalazal end. Presently 

 these tubercles push out into elongating nucleated cells, which 

 eventually develop into the long hairs of the coma. Now Godetia 

 permanently retains this tuberculated margin at the upper end, but 

 does not usually develop its coma any further. In the cases examined, 

 however, the forming ovules (either in reminiscence or prophecy) 

 stretched out their tubercles into incipient hairs. Tracing these 

 ovules in their subsequent development, it was found that these hairs 

 gradually disappeared until, when the ovules had become anatropous, 

 there was no indication of them. 



As Godetia has been merged into CEnothera, many species of the 

 latter were examined to see if any such thing occurred in them ; 

 but no trace of such growth was detected. This would seem to 

 indicate that if Godetia be not entitled to generic rank, it is at least 

 that part of CEnothera which approaches Epilohium. A discrepancy 

 must, however, be noticed here. In Epilohium the hairs of the coma 

 do not begin to form until the ovule has become completely anatro- 

 pous ; but in the Godetia observed the incipient coma had all disap- 

 peared by the time the ovule had become anatropous, beginning to 

 form before the nucleus is half covered by the coats. These hairs 

 appeared in gi-eatest size and abundance when the axis of the ovule 

 was at right angles to its anatropous position. 



Nectariferous Trichomes of Melampyrum.*— On the under side 

 of the bracts of Melampyrum nemorosum and arvense are minute scales, 

 in the former case colourless, in the latter a dark violet, which 

 E. Eathay has determined to be nectariferous glands, freely visited by 

 ants ; and similar organs occur also in other species of Melampyrum. 

 The secretion contains at least 2 per cent, of sugar, which does not 

 reduce copper-oxide in the cold. This secretion is rapidly replaced 

 if removed from the scales. In addition to ants, the secretion is 

 eagerly devoured by other hymenopterous insects, especially humble- 

 bees. The gland itself consists, in the species M. arvense, nemorosum, 

 pratense, and hnrhatum, of a short pedicel-cell and a circular peltate 

 disk, composed of a single layer of prismatic cells. They belong to 

 the structures called by de Bary epidermal glands ; since they excrete 

 a fluid on the upper side of the disk between the cuticle and the cell- 

 wall of the prismatic cells, which is freed by the rupture of the cuticle. 



With regard to physiological function, the author is unable to 

 agree either with the explanation of Kerner of the purpose of extra- 

 floral nectaries, that they attract insects which would otherwise attack 

 the flowers and other essential organs, or with that of Delpino and Belt, 

 that they attract insects which are hostile to and destroy those that are 

 injurious to the plant, but does not offer any explanation of his own. 



Threads of Protoplasm on Glandular Hairs of Silphium.t— 

 According to Dr. F. Ludwig, these hairs on the inner side of the 

 leaf of Silphium perfoliatum have been found to bear oscillating 

 * 'SB. k. Akad. Wiss. Wien,' Ixxsi. (1880) p. 55. 

 t 'Kosmos,' vii. (1880) p. 47. 



