XXXVI 



starved to death for want of food. It has often been stated that 

 mild open winters, cold ungenial springs, and rainy and sunless 

 summers are the chief causes of the diminution of the numbers of our 

 butterflies. Facts tend to prove that it is due rather to a conjunction 

 of unusually severe winters, and wet sunless summers. The last 

 specimens of Machaon, Crattegi and C -album taken at Glanvilles 

 Wootton were in the year 1815 and 1816. Let us consider that 

 period. The winter of 1813-14 was so severe that an ox was roasted 

 on the Thames, and the author of the "Journal of a Naturalist" in- 

 forms us that the summers of 1815, 1816, and 1817 were unceasingly 

 cold and rainy. C-albwn used also to occur abundantly near Hert- 

 ford previous to 1813, and at Epping about 1817 or 1818. Machaon 

 also used to occur in Hampshire, Somersetshire, Gloucestershire, 

 Glamorganshire and Yorkshire previous to 1819. Another species, 

 Polyommatus aeis became very scarce at that period, but it got com- 

 mon again in 1819 and particularly so in 1825 and also in 1835. Then 

 1836 had a very wet and ungenial summer in which only one specimen 

 was seen at Glanvilles Wootton, this was followed by a severe winter ; 

 after which the records in my father's journal are, a few in 1837, none 

 in 1838, scarce in 1839 and 1840, and a pair in 1841 (being the last 

 ever seen alive in Dorsetshire), which was another very wet year. 

 Another species not observed at Glanvilles Wootton after that year 

 is Thecla betulce. Now we arrive at another disastrous period, that of 

 the seven consecutive wet years 1875-1881, including the excessively 

 wet summer of 1879, and the severe winter of 1 880-81. Since those 

 years no specimen of Acts has been seen in Britain, nor any of Avion 

 except a few in 1884. C-album also almost disappeared, but in- 

 creased again in the Welsh and neighbouring counties of England in 

 1886. Cratagi disappeared at that period, the only specimens taken 

 since, being a few in Kent during the fine summer of 1887. 



The other two bad epochs, 1827-31, and 1860-63, appear to have 

 done nothing beyond thinning the ranks of various species. For in- 

 stance my father did not see one single specimen of Gonepteryx rhainni 

 during the whole year of 1861, and it was also scarce for two or three 

 years afterwards, as was also Phlaas. 



Other records of the scarcity of particular species are those of Napi 

 in 1868, a fine hot summer ; of Atalanla in 1845 ; of Janira in 1867 ; 

 and of Megara in 1860-63, during which tne species disappeared en- 

 tirely from large districts in the North of England and Scotland, in 



