26 MIDLAND NATURALIST 
there arose about twenty-four ordinary single headed dandelion 
scapes perfectly normal in every respect. 
The following year the plants were to a large extent again 
abnormal but the aggregates of heads were not as large as the 
preceding year, and were fewer in number. In succeeding years 
the phenomenon was not noticed as the lawn was kept closely 
cropped and special efforts made to eradicate all the dandelions, 
as the plant had by this time become quite a nuisance hereabouts. 
Owing to the fact that the spring was moist and warm and 
the locality was more than ordinarily manured in fall there is 
little doubt that the peculiar state of the plants was due to extra- 
ordinary conditions of nutrition. The specimen collected was as 
is evident from the plate very young and had not even attained 
to maturity in bloom. All the scapes were as yet brown in color 
due to the fact that chlorophyl in the scape and involucre had 
not developed. Specimens of plants with two or three heads on 
a scape are quite common but specimens like the one described 
are quite rare. Plants outside the small patch scattered over the 
rest of the lawn were to all appearances quite normal. 
Microscopy Notes. 
.l. SIMPLE METHOD OF EASILY RESOLVING MICROSCOPICAL 
TEST-OBJECTs. 
A. M. KIRSCH. 
Even the amateur microscopist has come to recognize that 
the value of a microscopical objective depends on the ease with which 
it will resolve with perfect clearness certain test objects usually 
diatoms with delicate markings. One of the most difficult of these 
diatoms as a test is Amphipleura pellucida Kg. the striae of which 
number about 96,000 to the inch. It is claimed that a good 
one-twelfth inch immersion lens will bring out these delicate lines 
to the vision, but the.writer has tried this with a number of such 
objectives under the various directions usually given, but always 
with very doubtful if any success. In experimenting for a long 
time with various objectives it was found that the fault lies not 
with the objectives, nor with the mounting medium usually balsam, 
but rather with the method of illumination of the test-object. 
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