168 
The pollen of one of the plants showed an unusually rapid response in 
the form of a very sudden rise in its hydrostatic pressure. That plant 
was Scabiosa atropurpurea which belongs to the Dipsaceae. Instantly 
almost, or before any measure of time could be made, when the pollen of 
this plant was placed in distilled water it instantly put out 4 tubes about 
the length of the diameter of the pollen grains. No further change took 
place no matter how long they were left undisturbed in distilled water. On 
the average 96 pollen grains in each 100 put out tubes suddenly in the 
way just described. For rapidity of response in this way the pollen of 
Scabrosa excells all other pollen thus far investigated. To be sure pollen 
Andrews, F. M. Proceedings of the Indiana Academy of Science 1917, ey alas} 
grains will often burst in a short time when placed in distilled water and 
the contents, as is well known, will be forced out more or less rapidly but 
none of them do so with the almost instantaneous action of Scabiosa. Nor 
do they maintain a tube form characteristic of the usual germinating 
methods in pollen. This sudden endosmotic action shown by the pollen of 
Scabiosa is an illustration of how quickly a membrane may be permeable 
even if only a slight amount of liquid enters. No change in the wall of the 
pollen as a dissolution had taken place. 
A WARMING NEEDLE FOR ARRANGING SPECIMENS IN PARAFFIN. 
BY 
EF. M. ANDREWS. 
The arranging of specimens in paraffin in the box of whatever kind used, 
must be done quickly and orderly before the cooling process begins. When 
the paraffin begins to chill in the box it becomes opaque due to air. At 
the same time when an ordinary needle is used that is not warmed to the 
same temperature or above the temperature of the paraffin in the embedding 
box the paraffin chills on the needle and accumulates on it with each at- 
tempt to such an extent that it must be cleaned continually or it is use- 
less. This difficulty I have overcome by the use of what I have termed an 
electrical needle. 
The needle itself consists of a No. 10 copper wire about 19 em. long, 
a small silver wire would be better, and is tapered to a point at the end 
which is to touch the specimens to be arranged. The other end is fastened 
to the electric wires. Beginning at this end the copper needie is wound 
with No. 22 enamelled resistance wire to within 3 em. of the point of the 
needle. This small wire is connected with the direct electric current and 
both the needle and enamelled resistance wire wrapped together with tape 
to a distance of 6.5 em. from the point. This needle was connected to the 
current with four 100 watt electric lamps in arranged multiple series which 
gave the necessary amount of heat. I found by experiment that the needle 
arranged as described acquired within about one minute 52 to 55 C. which 
is sufficient to keep the paraffin melted. If a higher or a lower temperature 
than 52 C. was desired then lamps having a greater or a less reststance 
