BOTANICAL GAZETTE. 225 



as that collected by Cohn and Gohi, and on sending a specimen to 

 the last named botanist he confirmed the correctness of the diag- 

 nosis. 



Mixed with the Minnesota Algse named above were fragments 

 of an Anabana, which appeared to be the form commonly known 

 as A. Flos-aqua'., var. circinalis, and also traces of a larger Ana- 

 bcena, the species of which could not be made out. In the Bos- 

 ton water works at South Frarningharn, Mass., Anabama gigantea, 

 Wood, was found in small quantity in the early part of Novem- 

 ber, 1882. I w r ould also record the discovery of Nostochopsis 

 lobata, Wood, by Messrs. E. Faxon and F. H. Hosford, at Fer- 

 risburg, Vt., where it was comparatively abundant and formed 

 expansions of several inches in water- courses. The occurrence of 

 Sphceroplcea, annulina should be recorded in California, where it 

 was collected by Mrs. Austin near San Bernardino. — W. G. 

 Farlow. 



General Conditions of Spontaneous Protoplasmic Movement, 



Dr. Chas. S. Dolley, of Rochester, N. Y., has just translated 

 Th. W. Engelmann's paper upon the "Physiology of Protoplas- 

 mic Motion," which has attracted so much attention. The fol- 

 lowing are the general statements under the above caption : 



1. Temperature. — For all contractile protoplasm there is a 

 higher and a lower temperature at which the spontaneous move- 

 ments cease under all circumstances. The minimum lies mostly 

 in the neighborhood of 0°, the maximum generally about 40°(C). 



2. Hygroscopicity. — In regard to this it is the same as re- 

 garding the temperature. There is, for all protoplasm, a maxi- 

 mum and minimum capacity for the inhibition of water. Close 

 determination is wanting, yet the minimum may average below 

 60 per cent., and the maximum over 90 per cent, Within these 

 limits the energy of the movements increases in general with the 

 amount of contained water, with a corresponding increase of vol- 

 ume, and diminution of the refractive coefficient. Rapid change 

 in concentration of the medium, causing rapid swelling, or more 

 specially shriveling, acts in a manner similar to irritants. 



3. Oxygen. — Protoplasmic motion is undoubtedly able to 

 continue in a medium entirely free from oxygen, but for a short 

 time only, at the most, some hours. The gradual stagnation can 

 at first be overcome by the introduction of oxygen, and by this 

 means alone. 



