53 General Kofcs. 
though to us it may be inappreciable. Dr. Goode mentioned anal- 
ogous variation in fishes, especially in the number of scales, the 
real usefulness of a greater or less number of these being unknown. 
Some families (as the Cyprinidaas) are remarkable for these varia- 
tions, while others {e.g. Perches) are noted for few or no variations, 
the species being very d stinct in all their characters. Prof. Eiley 
fully agreed with Prof. Ward. His studies of insects showed the 
existence of many variations which were undoubtedly useful, but 
at the same time many others the purpose of which was not in the 
least apparent. — Jos. P. James. 
Aster shortii. — Mr. E. S. Burgess has noted the occurrence of 
Aster shortii in the vicinity of Washington, D. C, a plant which 
had not been previously recorded. Prof. Ward in this connection 
mentioned he had found a species of Lemna new to the flora, and Dr. 
Vasey said he had found a species of Festuca not before known from 
the locality.— Jb5. F. James. 
'' Causes of Cojf figuration of Trees."— Prof. Fernow, Chief 
of Division of Forestry, read a paper upon this subject. He ex- 
hibited several photographs of trees growing upon the sides of hills 
The trunks of these formed nearly a right angle with the slope, and 
the branches were parallel with the slope. It was suggested by 
Prof. Ward that possibly the photographs represented an abnormal 
mode of growth, and that they were due to unusual conditions. It 
-was also suggested that the peculiar direction of growth of branches 
ivas due to the cropping of cattle. Few of those present had ever 
seen trees similar to these, and most were inclined to the opinion 
that they represented something abnormal. — Jos. F. James. 
The Need of Making Measurements in Microscopical Work. 
— It is greatly to be desired that all workers with the microscope 
should make much more general use of the micrometer than is now 
the custom, particularly in botany. It is still a common thing to 
find descriptions of tissues accompanied by plates or figures with 
little to guide the reader as to the'absolute size of the objects. In 
this the fathers sinned more than we. but we are by no means sin- 
less, as may be seen by 'aking up almost any descriptive paper on 
botany. Cells, cell masses, filaments, hyphae spores of all kinds, 
pollen cells, etc., etc., should all be subjected to careful measure- 
ment. We may say that so many measurements are needless, but 
so the older botanists thought, greatly to our present discomfort. 
In our botanical laboratories the student should be not only 
taught to make measurements of everything he studies, but the 
making of such measurements should be a part of the study of the 
object. No laboratory microscope should be used which does not 
have as one of its accessories always at hand an efficient micrometer. 
Such a micrometer need not cost much. A simple disk of ruled 
glass dropped upon the diaphragm of the eye-piece will answer 
