138 



one who has tried this will recognize how difficult this seemingly 

 simple operation is. In order to accomplish this successfully, a 

 second microscope was taken (it happened to be an old model 

 without rack and pinion), and was divested of its tube. On the arm 

 a piece of wood was wired and the object-holder — in this case 

 a test-tube — firmly fixed to it. The two microscopes were 

 brought together as shown in the figure and constituted in com- 

 bination a horizontal microscope. By means of the micrometer 

 screw on the microscope carrying the object, its vertical position 

 could be regulated to a nicety and both of the microscopes being 

 level as to their bases, no errors other than those inherent in 

 such instruments are met with. Of course if the object being 

 measured is itself not vertical, the usual difficulties will be met 

 with. One can only take the usual precautions against this. 



A REMARKABLE PHYSALIS 



By Robert F. Griggs 



For nearly ten years the very peculiar Phy sails described 

 below has lain, undiscovered, in the National Herbarium. It had 

 been labelled Physalls Fendlcrl but its flowers are five times 

 smaller than in that species. Probably whoever made the first 

 identification never saw the flowers at all and it is not to be 

 wondered at that he did not for they would hardly be noticed 

 except on careful search or by accident. It was by the latter 

 that the writer found one of them after having previously exam- 

 ined the sheet more than once in connection with other work on 

 the genus. Search revealed several more — all of the same de- 

 gree of minuteness. There is but one sheet, but there seems to 

 be no reason for supposing it to be a freak or abnormal in any 

 respect as the fruits are entirely ordinary and like others of the 

 genus. Hence the following name and description are offered. 



Physalis minuta sp. nov. 



Perennial from an underground stem, spreading, forming small 

 tufts or mats on the ground ; branches not more than 30 cm. 



