se 
316 BOTANICAL GAZETTE foctom 
and of irregular division being quite parallel to the production of the palmella 
form in my alga, which is brought about by many metal salts as well as by high 
osmotic pressure of the medium. Perhaps if Horn’s poisoned material had been 
transferred to a normal medium at an early stage in the development of cross 
walls the same cellulose formation would have occurred as that which he observed 
in the partially plasmolyzed filament. 
Regarding the production of zoospores, the unsatisfactory and almost meat- 
ingless general observation is made again, as it has been made with other forms, 
that these bodies are produced ‘‘when a sufficient amount of nutrient material 
‘for growth is no longer present in the medium.” This is of course not exact 
science. They are produced at a temperature of from 5° to 31° C. “Osmotic 
pressure has only an indirect effect.” Intercalary sporangia are produced in the 
filaments poisoned with metal and also in those which have been partially plas 
molyzed for a short time; indeed, all the cells of the parenchyma-like masses above 
described seem to be potential sporangia. This last observation seems to agit 
quite accurately with that made in the case of Stigeoclonium, that palmella cells 
are capable of producing zoospores when in weak media, whether the plant has 
been brought to this form by metallic poison or by external osmotic pressure. 
These are the main results of the paper. It is to be regretted that good 
experimentation should be brought to so little account by such vagueness 
thought as indicated in the adoption of NAGELI’s theory of the oligodynamic effec 
of metals, which has no real basis in experiment, and the idea that nutrition 8 
somehow a thing apart from chemical stimulation and response. The ap 
paper appears to ‘‘strike only the high places,” as the phrase — seb 
needed in physiological work is more of the methods of the physical chemist 
B. E. Lrvincston. : 
Lawsons® has published the results of his investigation of pein 
japonica, concerning which we have had heretofore only ARNOLDIS = on the 
meager account. The material was obtained chiefly from trees pears 
campus of Stanford University. The staminate cones appear early m uae 
the reduction division occurs the first week of November, and bas jon takes 
the microspores are rounded off. In January the first nuclear i sal 
place, resulting in generative and tube nuclei, no prothallial ce being 
ob 
Deep in the nucellus three or four mother-cells become Rae of 
in March, each giving rise to a tetrad. The centrally ee el 
twelve to sixteen potential ones functions, the development © 
CC er of Cryplomer 
38 Lawson, A. A., The gametophyte, fertilization, and embryo 
japonica. Annals of Botany 18:417-444. pls. 27-30. 1904- 
