The RURAL NEW-YORKER 
803 
What, 205 bushels increase per acre just by spray¬ 
ing! Yes, and on a three-acre piece, too. Blakeman 
is a hustling young potato grower, and believes in 
growing ceidified seed of the best obtainable. The 
unsprayed rows only yielded 236 bushels per acre. 
Figs. 312, 313 and 314. all of this field, tell the whole 
story. Fig. 312 shows the field September 1. ap¬ 
parently in a vigorous, healthy condition, but the 
checks rows in the left center of the picture are 
badly infested with late blight, which is just devel¬ 
oping. Fig. 313 shows the same thing on September 
17. The check rows have been dead for some time. 
The same field is shown in Fig. 313 on October 2. 
The sprayed portion of the field is still 
growing. Four to five weeks longer 
growing period accounts entirely for 
the hig difference in yield. 
INCREASED YIELD.—An increase 
of 250 bushels is unusual, you say. hut 
let us look at that table again. We 
note that there are eight fields that 
gave increases of over 100 bushels per 
acre, and several others a little short 
of that amount. In fact, 15 of the 30 
fields averaged 108 bushels increase by 
spraying, and if you look carefully you 
will note that the fields giving the 
highest yields per acre almost without 
exception give the biggest returns per 
acre for spraying. In other words, the 
best fields of potatoes pay bigger divi¬ 
dends when sprayed properly. For 
further proof of this we find that the 
five highest yielding fields average 352 
bushels per acre, and the increase due 
to spraying was 131 bushels per acre. 
On the other hand, the five lowest 
yielding fields only averaged 170 bushels 
per acre, and the increase was only 
35% bushels per acre, a difference of 
95 bushels between the increases of the 
two groups. Diseased seed had much 
to do with those poor yields, as these 
fields were badly infested with mosaic, 
leaf roll, etc. don w. ward. 
(continued next week) 
1 tested 100 eggs, or tested eggs until 1 had 100 
which the tester said were pullets, using the article 
attached to the stock screwed in the vise, and get¬ 
ting the fairest test. I could. The eggs were hatched 
April 19. a test at the tenth day showing seven 
infertile. I toe-punched the chickens and have just 
examined them. I found 30 pullets and 22 cockerels 
New York. c\ a. x. 
Fish for Killing Mosquitoes 
the mosquitoes, which spread yellow fever. Oil was 
used on all stagnant ponds and pools, but tliis inter¬ 
fered with the habits of the people. Then the little 
fish known as top minnows were put into the water. 
r l hey cleaned up the mosquitoes promptly. The 
Bureau at Washington publishes several pamphlets 
which give much information about fish and mos¬ 
quitoes. Speaking of the top minnow the Bureau says : 
'1’ln' top minnow Gambusia ranges from Delaware and 
Southern Illinois southward to the Gulf of Mexico, and 
will not survive the more northern Winters. One of the 
investigators of the United States Bureau of Fisheries 
has adopted a method of procedure for utilizing them 
in ornamental and other small ponds. It is simply to 
A Test of a “Sexotester 
S OME time ago mention was made In 
The R. N.-Y. of the “Sexotester.” 
The name was new to me. hut I think 
I had met the article. Last March a 
neighbor asked me how I would like an 
article that would tell a fertile egg 
before it was placed in the incubator, 
and also tell the sex of the chicken il 
would hatch. I told him I would like 
it very much, but “there is no such 
animal.’’ lie replied that he had a 
little article which a person who came 
in his place of business a few days be¬ 
fore was selling, saying il certainly 
would tell the sex of animals, and he 
asked me to try it on eggs. I told him 
I would make a test of it the next day, 
or, rather, test eggs with it that 1 ex 
pected to put in an incubator. 
It was a small pencil-shaped article, 
filled with a cement substance, and 
attached to a short silk thread. The 
one making tin 1 test was to hold it by 
the thread above the egg or animal. 
If a male the tester would swing across 
and back. If female it would swing in 
a circle. Using animals, or persons, it 
worked as he said, or apparently did 
so, though I was suspicious that the 
person holding it helped the swing, per¬ 
haps involuntarily. I tried my best not 
to do so. Using it above a male animal 
if I purposely swung il in a circle and 
then held my hand as steadily as pos¬ 
sible, it would slowly conn 1 to a stop 
and then start swinging across and back as it should 
do for a male. 
To be sure not to influence the swing I screwed 
a piece of wood in a vise and passed the thread over 
one end of the stick. Then by taking hold of the 
thread and stick it would work, hut was much slower 
starting than when held free in the hand. But with 
eggs it was different. It worked the same on infer¬ 
tile eggs as on fertile, and was very slow starting 
at all. If I started it swinging across an egg it 
would continue to swing that way, and if I started 
it swinging in a circle on the same egg it would 
continue swinging in a circle. 
Under “Brevities,” page 714. I see that mention is 
made of a fish known as the top minnow (Gambusia) ........ t .. 
which will exterminate mosquitoes. Can you give mo catch a few hundred of the fishes in the Fall and keep 
them over Winter in a greenhouse as a 
brood stock. Fifty or so of them planted 
outside in April or May, when the water 
reaches a temperature of about 60 de¬ 
grees, may have increased to several 
thousand by August, when Anopheline 
larvae are becoming plentiful. Any com¬ 
munity could carry out this practice. All 
that is required is a small minnow seine, 
a couple of milk cans and several tubs or 
half barrels kept in a greenhouse. Any¬ 
one familiar with the management of an 
aquarium can feed and care for the brood 
stock during the Winter. 
The use of these little fish is based 
on the fact that mosquitoes pass one 
stage of their life in stagnant water. 
The larvm or “wrigglers” are often 
seen in shallow water, and they are 
greedily eaten by these little fish. This 
minnow does not lay eggs, hut gives 
birth to well-developed and active 
young, sometimes producing five to six 
broods in a year. Some great stories 
are told about the appetite of these 
little fishes. In one case a single min¬ 
now disposed of 140 mosquito larva* 
inside of 24 hours. Many cases are on 
record where stagnant ponds, well 
filled with young mosquitoes, were com¬ 
pletely cleaned out by putting these 
fishes in the water. In larger ponds 
where there are spaces of clean gravel 
shores the common sunflsli or pumpkin- 
seed will kill many of the young mos¬ 
quitoes. Goldfish are also said to he 
good at Ibis work. The little top min¬ 
now would not he of great service 
north of Delaware, but through the 
South he might be made very useful 
as a mosquito hunter. 
Sprayed Rows to Right; Unsprayed to Left, September 1. Fig. 312 
Same Field September 17; Unsprayed Rows Dean. Fig. 313 
Same Field October 2; Sprayed Rows Still Growing. Fig. 314 
further information concerning this, or refer me to 
where I can get it? 1 would like to know whether it 
would live iu this climate and in our environment, and 
really prove effective; also whether it would do any 
harm to other fish. If it would not, would it survive 
where there are other fish, or would certain kinds kill 
it? How could some of these fish be secured to give it 
a trial? Does it multiply quickly? I am interested, 
not for private but for public reasons. Being on the 
executive committee of our Norfolk County Farm Bureau. 
I felt mat if it were anything practical that we could 
introduce here we would like to do it. n. C. c. 
Massachusetts. 
o 
>UR information came from the Bureau of Fish¬ 
eries at Washington. The story was that efforts 
were made in a Central American province to kill 
Farm Fish Breeding 
W E Americans have many reasons 
to be proud of our achieve¬ 
ments. But we could take lessons in 
other things from those who specialize 
in the things which we neglect. 1 will 
mention but two instances to illustrate. 
One is the culture of cels at Comaccihio, 
on tin* Adriatic. There the people have 
built ponds with fresh water running 
through them, have connected the 
ponds with the Adriatic through canals. 
These have flood gates. At proper 
limes these gates are opened to allow 
eels to pass through. The eel goes into 
salt water to feed, but breeds in fresh 
water. The people cater to his desires. 
At tlie proper time they close the gates 
and harvest the eels. They sell $60,000 
worth per year caught in that way. 
The Scotch are not slow. From one 
pond, close to the river Dee, they sell 
yearly $6,000 worth of fish. No coun¬ 
try affords better opportunities to do 
these tilings than ours. History tells 
that the Romans, at Tusculmn, built 
fresh water ponds with streams flowing 
through them. They connected the 
ponds with salt water by canals. Salt 
water lish came into the ponds to breed 
in such quantities that the whole coun¬ 
try had fresh fish on every table as a 
common thing. Our rivers were once 
filled with salmon, shad and herring. They are not 
now, because the rivers are polluted by refuse from 
factories. We have thousands of places where wt* 
could make artificial breeding places for them and 
make fish a very common article of diet. It is 
especially appropriate now. when the fish trust robs 
people to Hie tune of $1.50 for u shad. The writer 
remembers when farm wagons were driven to tide¬ 
water and filled with shad at four cents each, her¬ 
ring at corresponding prices. The farmers salted 
them or smoked them for a season’s supply, it 
would bankrupt a farmer now to fill his wagon with 
shad. The ocean lias tin* same supply, but the 
