114 RECORD OF CURRENT RESEARCHES RELATING TO 



D. By fissures in the epidermal layer. 

 a. On a smooth epidermis. 



a. Level. Acer pseudo-platanus, SympJiytum officinale, Par- 



nassia palustris. 

 /3. Elevated. Epilohium angustifolium. 

 h. On a rough epidermis; depressed. Anthriscus sylvestris, 



Heracleum S])liondylium, Pastinaca sativa. 

 c. On a very uneven epidermis. Aralia Sieholdii. 



The term " metaplasm," as previously employed by Hanstein, is 

 apj)lied in this paper to the fluid or semifluid contents of the nectary, 

 which serve for specific physiological functions, and are subject to 

 transformations, sometimes of a very deep-seated character. The 

 metaplasmic substances vary greatly in chemical and physical pro- 

 perties, dependent on the relative proportion of carbohydrates and of 

 albuminous substances. 



Connection between the Arrangements of the Floral Organs 

 and the Visits of Insects to Flowers.* — In continuation of his inves- 

 tigations of the physiological functions of the nectaries of flowers,| 

 M. Bonnier gives the following as his general conclusions as to the 

 connection of the arrangements of the floral organs with the visits of 

 insects : — 



1. The form of the corolla may be materially modified without 

 offering any obstacle to the visits of insects. 



2. Very different insects may visit the same species. The nature 

 of the visiting insects varies with the locality, just as the amount of 

 nectar produced varies with the latitude and altitude. A nectariferous 

 plant which is visited by insects in one region may be destitute of 

 nectar and unvisited in another region. 



3. The development of hairs in the interior of the corolla, as in the 

 LabiatEB, or of scales or internal spurs, as in the Borragine», is not 

 correlated to that of nectar. 



4. Insects very often visit flowers without effecting cross-fertiliza- 

 tion, and even without producing any fecundation. They frequently 

 collect a saccharine fluid outside the flowers. 



5. Visiting insects go where the nectar is most abundant and most 

 easy to obtain ; their visits have frequently no relation to the floral 

 arrangements which facilitate cross-fertilization. 



Arum crinitum as an Insectivorous Plant.J — The spathe of this 

 plant, when in flower, exudes a powerful odour of putrid flesh, attract- 

 ing to it quantities of flies which lay their eggs at the bottom of the 

 spathe. The similar visits of insects to the spathe of Ai-um maculatum 

 are described by Sir John Lubbock as having for their object the 

 transference of the pollen to the female flowers ; but M. B. Schnetzler 

 believes that in the case of A. crinitum this is, at all events, only a 

 secondary purpose. On the spadix of this species are a number of 



* ' Bull. Soc. Bot. France,' xxvii. (1879) p. 68. 

 t See this Journal, vol. ii. (1879) p. 748. 

 X ' Comptea Rendus,' Ixxxix. (1879) p. 508. 



