74 SCIENCE 
“ A new proof of the existence theorem for im- 
plicit functions,” by G. A. Bliss; “On a set 
of kernels whose determinants form a Stur- 
mian sequence,” by H. Bateman; “On the 
cubes of determinants of the second, third 
and higher orders,” by R. E. Moritz; “ Note 
on the maximal cyclic subgroups of a group 
of order p™,” by G. A. Miller; “ An expression 
for the general term of a recurring series,” by 
Tsuruichi Hayashi; “Shorter Notices”: 
Lebon’s Biographie et Bibliographie of Emile 
Picard and Paul Appell, by J. W. Young; 
Vermeintliche Beweise des Fermatschen 
Satzes, from the Archiv der Mathematik und 
Physik, and Lind’s Ueber das letzte Fermat- 
sche Theorem, by Joseph Lipke; Slaught and 
Lennes’s Solid Geometry, by F. W. Owens, 
Hawkes, Luby and Touton’s First Course in 
Algebra, by J. V. McKelvey; “ Corrections”; 
“Notes”; “New Publications.” 
WHEAT RUSTS AND SUNSPOTS 
In looking over a copy of the Journal of 
the Agri-Horticultural Society of Western 
India for April to June, 1906, I was interested 
to notice, on page 165, an article with the 
above caption, by G. N. Sahasrabudhe, of the 
College of Agriculture at Poona. The au- 
thor refers to a report in the Proceedings of 
the Australian Wheat Conferences of period- 
icity in the occurrence of Puccinia graminis 
in Australia. The years of the most severe 
attacks, it is stated, were 1867, 1878 and 1889, 
making a period of eleven years between every 
two maximum years. The writer goes on to 
state that this cycle suggested to some mem- 
bers of the conference that it had some rela- 
tion with the various phases through which 
the fungus has to go, but quotes from Sur- 
geon-Major D. Prain the statement that “the 
periodicity is not due to any inherent property 
of the fungus, but must, as seems to be the 
belief in Chili, be due to the recurrence of 
conditions favorable for its development.” * 
I quote the following paragraph entire: 
We have trustworthy records of rust attacks in 
Australia from 1867. In that year it was almost 
1 Apri. Ledger, No. 16 of 1897, p. 9. 
[N.S. Vou. XXXV. No. 889 
general and caused immense loss in South Aus- 
tralia. This is the minimum year of the sun-spot 
eycle (1867-78). The year 1878 was one of the 
worst years for rust in Victoria, and in South Aus- 
tralia it prevailed over a large area that year; that 
also was the minimum year of the sun-spot cycle. 
In South Australia 1880 was the year when a con- 
siderable area was affected; and it was the year 
when the sun-spot area was very small. The 
seasons 1882-1888 seem to have been very free 
from rust; and that was the maximum period of 
the sun-spot cycle (1879-1889). In 1889 it was 
almost general and caused great loss in South 
Australia, Victoria, New South Wales and Tas- 
mania; and that was the minimum year of the 
sun-spots. This clearly proves that the attack of 
the pest is most severe when the sun-spot area 
is the smallest, and from the theory of the sun- 
spots it does not seem unnatural. It is well known 
that the changes in sun-spots are closely related 
to the changes in the atmospheric pressure and 
consequently in the rainfall; and experience shows 
that the development of the fungus is dependent 
to a great extent on the atmospheric conditions 
and rainfall. The opinions of the farmers put 
forward in the Second and Third Conferences 
indicate the same thing. Rust is usually most 
prevalent in seasons when the rainfall is excessive, 
especially during October and November.2 When 
close, damp, muggy weather sets in, the rust is 
certain to appear (indicating diminution in pres- 
sure). A dry cold season in Queensland is inim- 
ical to rust. The year 1889, which was a very 
rusty one, was marked in New South Wales by 
frequent thunderstorms at the time the wheat was 
in bloom. The colder districts were in that year 
less rusty than others. 
The author states that when he thought the 
matter over, especially the remark by Dr. 
Prain, he thought there must be some rela- 
tion between this eleven-year cycle and the 
Brookneyr’s cycle of sunspots, which is also of 
eleven years, and that when he began to com- 
pare the two cycles closely, he was “ almost 
convinced ” that there must be some relation 
between sunspots and the growth of the Puc- 
cinia fungus. This relationship, he concludes, 
may “throw a great light on the life history 
of the fungus and also we may be able to fore- 
tell the years in which the rust attacks will 
* Proce. of II. Con., 17, 49. 
