284 THE ZOOLOGIST. 



zoological. The communication by Mr. T. L. Palmer on " The Danger of 

 introducing Noxious Animals and Birds " is well worth the most careful 

 perusal. Some facts relating to accidental or involuntary migration may be 

 repeated. " In November, 1895, a Central American Mouse of the genus 

 Oryzomys, concealed in a bunch of bananas shipped from Puerto Limon, 

 Costa Rica, was captured alive in a commission house in Washington, D. C. 

 A young murine Opossum from Tropical America was discovered in a bunch 

 of bananas at Ames, Iowa, during the summer of 1882, and was kept alive 

 for some time. If such cases were frequent, it can be readily seen how a 

 species might gain a foothold in new regions, provided the conditions were 

 favourable for its increase." Members of the Sparrow cult will not find 

 agreeable reading in the account of " the true character of the bird " as 

 detailed in these pages. The expenditure for its destruction in Illinois 

 . (1891-95) and Michigan (1887-95) amounted to about 117,500 dols. The 

 introduction of the Sky-Lark (Alauda arvensis) and the Blackbird (Turdus 

 merula) into New Zealand, where the first has become the scourge of the 

 turnip field, eating the seeds soon after planting, and the second is well 

 known as a champion fruit destroyer, induces the remark that both these 

 birds " are noted singers ; but the charms of their song hardly compensate 

 for damage to crops." 



Mr. J. W. Willis Bund has republished a paper read at the Victoria 

 Institute, Worcester, on " The Life of a Severn Salmon." Much has still 

 to be learned respecting this fish, as we read that no one can give a really 

 satisfactory statement as to the length of time a Salmon will live if it 

 escapes death by the hands of its numerous enemies, nor can tell with 

 accuracy the time it takes to produce a twenty-pound Salmon. We cannot 

 say we know even the outlines of the life-history of a Salmon in fresh water. 

 " A question of some interest arises as to the age to which a Salmon will 

 live. Here again more evidence is wanted ; a twenty-pound fish cannot be 

 less than four years old, and is probably older. He would be hatched out, 

 say, in 1890, would descend as a Smolt in 1891 at the earliest, and perhaps 

 not till 1892. If he went down in 1891, he would probably return as a 

 Grilse in 1892, as a Grilling in 1893, as a Salmon in 1894 ; but he might 

 not go down till 1892, and his return in any of the stages might be pro- 

 longed, so that it will be safe to say that a twenty-pound fish is probably 

 seven years old, aud very possibly older. One fact seems clear, that the 

 male Salmon grows larger, and so presumably lives longer than the female ; 

 it is the exception to get a female Salmon over thirty pounds, while it is 

 common to get males over that weight. Why this is, I cannot explain ; I only 

 state the fact. Against this must be set the assertion that at spawning-time 

 the mortality of males is said to be greater than the mortality of females," 



