364 BOTANICAL GAZETTE [MAY 
and the different speeds at which the same part grows at different times. The great- 
est variety in the rate of growth exists, as I suppose is well known, and of course the 
kinetoscope brings out the relative rates of growth in a very truthful and graphic 
MANNER. 6. 42)4 t the present time I am preparing some additional films taken from 
growing seeds. Of course there is no reason why the photographing should not be 
continued until the plants have bloomed and fruited, if any fact important to mechan- 
ics or botany is likely to result from the trouble. Perhaps botanists know of matters 
in plant growth and plant lop t that it may pay them to investigate by the same 
thod. I anticipate that some interesting facts concerning the mechanics of the 
root’s motion into and through the soil will result from such studies. 
Mr. ALBERT F. Woops, of the U. S. Division of Vegetable Physiology 
and Pathology, has found that chlorophyll is rapidly destroyed by oxidizing 
enzymes, which are normally present in small quantity in many of the higher 
plants. Under unknown conditions these enzymes become more active or are 
produced in larger quantity, causing disease marked by variegation, such as 
the mosaic disease of tobacco, which may be produced at will by inocula- 
tion with germ-free virus from diseased areas, and by cutting back healthy 
pot-grown plants which have about exhausted the soil in the pot and allowing 
only one shoot to develop rapidly in a high temperature under copious water- 
ing. The lighter areas invariably show the presence of larger amounts of 
some substance which turns a solution of gum guaiac blue. This reaction 
Mr. Woods accepts as indicating the presence of oxidizing enzymes, though 
aware that it has been considered unreliable. The oxidase and peroxidase 
may remain in soil uninjured for several months. The latter diffuses readily | 
in plant tissues or agar plates, and may be dried without injury.” 
In a short note in Sczence 11:17-19. 1900, Mr. Woods presents reasons 
for believing that in the mosaic disease of tobacco leaves the lighter colored 
areas contain more starch than the healthy tissues because the greater 
amounts of oxidase they contain partly or wholly inhibits the action of trans- 
location diastase.— C. R. B. 
PROFESSOR D. H. CAMPBELL has published some of the results of his 
studies of Aracee in the current Annads of Botany (14: 1-25. Pls. 3- 1900). 
Species of Dieffenbachia and Aglaonema were the forms from which he 
obtained the most complete results, although very many gaps remain to be 
filled even in them. In both of these cases the axial origin of the ovule 
seems undoubted, and this probably represents a primitive condition. One 
certainly often appears when no embryo is formed. In the whole family ther 
is also a tendency for the antipodal cells to develop strongly, often dividing 
™Centralbl. f. Bakt. 57: 745-754. 1899. 
