The Irish Nahu^alist. 
April, 
disease, and then the}' die off, sometimes so quickly that, as 
Blasius puts it, the whole race seems to have disappeared 
from the earth as if by magic. In the same way, it appears 
that wherx toads become extremely numerous, as they did in 
South Wales in 1872, they are attacked by a disease which is 
believed to be caused— at any rate it is aggravated — by blue- 
bottle flies. In 1872, according to observations lately quoted 
by Mr. Distant in the Zoologist^, there was quite an 
epidemic of this disorder among the toads about Tenby, and 
in the following year very few toads could be seen ; but those 
that were seen were free from disease. I have a note of my 
own, taken in May, 1881, that bumble-bees were at that time 
unusually abundant in Co. Wexford ; but they were succumb- 
ing in great numbers to the attacks of parasitic enemies, from 
which none of the bees seemed free ; the walks were strewn 
with dying and helpless bees, whose misfortunes were, I 
believe, largely a consequence of their own excessive numbers. 
If the red clover had suffered in consequence, it would have 
been almost possible to argue that cats, which v.'ere rather 
numerous in the neighbourhood, had done the clover harm by 
destroying too many of the mice that might otherwise, by 
their ravages, have prevented the bumble-bees from becoming 
too abundant for their own health. Then it may be remem- 
bered that in the autumn of 1897 there were many letters in 
the Irish Naturalist and elsewhere on the great scarcity of 
wasps. Most of those who wrote testified that they had never 
known such a scarcity ; but the previous year, the hot dry 
summer of 1896, had been remarkable for the enormous 
numbers of wasps, and so had the spring of 1897 itself for the 
number of queens, of which Mr. R. M. Barrington's figures 
showed that the number destroyed at Fassaroe that spring 
broke his record. I may add that a similar superabundance 
of wasps in the autumn of 1898 and the spring of 1896 was 
followed by a similar remarkable absence of wasps, at least in 
Co. Wexford, in the autumn of 1899. I do not think these 
abrupt changes are accidental.^ I would go a little further 
1 Vol. ix. (4th ser.) 1905, p. 338. 
^ Mr. Barrington has since informed me that the number of queen 
wasps destroyed at Fassaroe in the spring of 1905 was yet greater than 
in any previous year, and during the autumn that followed there were 
again practically no wasps. 
