| 
| 
1906] CURRENT LITERATURE 219 
Chloroplasts of sun and shade plants. —LuBimENKO” refuses to accept as a 
general law the statement formulated by Turriazerr that the maximum photo- 
synthesis occurs under an intensity of psiaenian ome to renee one half that of 
direct insolation. By measuring the rate of phot hilous plants 
(Tilia and Abies) and of ombrophobous plants (Betula and Pinus) under both 
artificial and natural light he finds that plants differ as to the minimum insolation 
necessary to initiate photosynthesis. In this result the author finds basis for the 
conception of a specific quality of the chloroplasts. Further investigation coh- 
vinces him that the curve of photochemical work is determined primarily by the 
specific quality of the chloroplasts and by the anatomical structure of the leaf. 
The influence of the latter factor is particularly evident during periods of moderate 
sunshine, but the potency of the former is manifest under insolation of high or low 
intensity. 
The chloroplasts of the ombrophilous plants have greater dimensions and a 
sensibility almost five ne Lereaiet than that of ie ca ameaamne of ese ena 
plants. Other test te that the pig 
roplasts of the former. : 
While auxiliary data support the author’s main conclusion, the chance of error 
through imperfect technique and ignorance of all the factors is so great that final 
conclusions are better withheld—RayMonD H. Ponp. 
Microsporangia of Sphenopteris.—It has been suggested that the microspo- 
rangia of Lyginodendron Oldhamium =Sphenopteris (Crossotheca) Héninghausii 
might be found on Telangium Scotti. K1pston"s concludes from its structure that . 
Telangium Scotti cannot be the microsporangia of Sphenopteris Héninghausii. 
In no instance was organic connection between the two demonstrated. 
He found a few microsporangiate pinnae referable to Crossotheca Zeiller in 
organic connection with barren pinnae of Sphenopteris Héninghausit. The fertile 
pinnule is oval, entire, and attached to the rachis by a short pedicel, which is thick- 
ened very slightly upwards before merging into the pinnule, to which it seems 
to be united fora short distance. The pinnules appear to be rather thick, and the 
vascular bundle which enters the pinnule divides into two branches, which separate 
slightly from each other. Each fertile lobe bears six to eight broadly lanceo- 
late, sharply pointed, bilocular microsporangia, which in early stages bend inward, 
forming a small hemispherical bunch, with their apices meeting in the center, 
Later, the microsporangia spread outward and appear as a fringe hanging from the 
margin of the pinnule. The microspores are either slightly oval or circular and 
Measure 50 to 75 “ in diameter. The walls are roughened, being covered with 
minute blunt points. The tri-radial ridge, marking the line of cleavage of the 
tetrads, is sometimes apparent.—W. J. G. Lanp. 
12LUBIMENKO, M. W., Sur la sensibilité de 1’ ig chlorophyllien des plantes 
ombrophiles et ombrophobes. «Rev. Gén. Bot. 17: 381-415. pls. 10, 11. 1905 
™3KipsTON, R., Preliminary note on the occurrence 3 microsporangia in organic 
connection with the foliage of Lyginodendron. Proc. Roy. Soc. B76: 358-360, pl. 6. 1905. 
