JuLy 26, 1918] 
periments made on two specimens in a tent 
with a flashlight and observations made in the 
Philippines concludes that the synchronism 
in the flashing of a group of fireflies is ac- 
cidental and of very rare occurrence 
Mr. Olaf O. Nylander, of Caribou, Me., to 
whom I sent a copy of my firefly article, in a 
letter dated October 8, 1916, says that a num- 
ber of years ago, while walking from Caribou 
Mills to his home, he noticed in a small clear- 
ing the greatest assembly of fireflies that he 
had eyer seen; the ground and stumps were 
fairly aglow. The flashes were not perhaps 
as regular as an army officer would like to see 
in regimental drills but were so rhythmic that 
any one would take note of their action. He 
also observed that the air was very damp at 
the time. 
In The Scientific American of January 19, 
1918, Mr. John V Purssell, of Washington, 
D. C., records that 
In the town of Cotabato, Island of Mindanao, 
P. I., a few years ago, there were two trees about 
the size of apple trees, and perhaps a hundred feet 
apart, and every evening these were filled with fire- 
flies which flashed in synchronism, first one tree 
lighting up and then the other. There must have 
been several thousand insects in each tree, yet the 
synchronism was so perfect that rarely or never 
did a single firefly flash at the wrong time. 
To the best of my recollection the illuminated 
period lasted about two or three seconds and the 
dark period perhaps twice that long. I can posi- 
tively vouch for the accuracy of the foregoing for 
it seemed so strange, and produced so beautiful an 
effect that I thought it one of the most remark- 
able things in the Philippines, and it made a deep 
impression on me. 
The independent observations of this syn- 
chronism in the flashing of fireflies by the 
author in Gorham, Me.; K. G. Blair in Eu- 
rope; S. Shelford in Borneo; Dr. H. C. Bum- 
pus near Woods Hole, Mass.; H. A. Allard in 
Oxford, Mass.; Olaf O. Nylander in northern 
Maine and John C. Purssell in Mindanao, 
Philippine Islands, are I think quite sufficient 
to establish the fact that these insects do at 
times flash in unison. The rarity of the oc- 
currence is a mystery. 
In this connection a coincidence might ex- 
SCIENCE 93 
plain a well-known occurrence in a small 
group of individuals, as at a dinner party 
when they all cease talking for an appreciable 
time, but would not explain the quiet pause 
which one sometimes observes in a large din- 
ing hall containing hundreds of diners. I 
discovered the cause of this phenomenon some 
years ago. While dining with a number of 
friends at the Parker House the guests at a 
neighboring table had been noisy, even boist- 
erous, doubtless we had been somewhat noisy 
too. The neighboring table suddenly became 
quiet and we stopped talking to see if the 
noisy ones had gone, but they were still there, 
other tables looked about for the pause and 
this hush spread rapidly through the hall. 
Dear old Dr. Virchow had often observed this 
pause and thought my explanation correct. 
He also told me that it was a saying in his 
country that when this hush occurred an angel 
was passing through the room, also that a 
lieutenant was paying his debts! So in re- 
gard to fireflies a dozen or more might flash 
for awhile in unison as a coincidence, but 
when thousands are observed to flash in unison 
no doctrine of probability or chance can ac- 
count for it. 
Epwarp 8. Morse 
SALEM, Mass., 
July 2, 1918 
THE VERO MAN AND THE SABRE TOOTH 
In determining the relative antiquity of the 
Vero man and the fossil plants and animals 
there associated, certain larger factors yet 
require attention. The direct evidence has 
been minutely examined from varying points 
of view: geologic, paleontologic, anthropologic. 
It seems conclusive that the man of Vero 
reached one of the last lairs of the sabre- 
toothed tiger, as Dr. Hay contends; while 
Berry discloses a degree of change in the local 
flora not to be ignored. But, on the other 
hand, the anthropologists show that the ac- 
companying artifacts are like those elsewhere 
recent. 
Perhaps the anthropologists have the best 
of the argument, as such. Florida has re- 
tained much its present outline since the close 
