Notes on Natural History. 177 



which come the small velvetv galls on the buds, and that the flies emerging from 

 those velvety hud (jails in May lay the eggs on the leaf from which come the 

 apple galls in July. Dr. Addler has thus established the connexion of these two 

 forms. And by the same careful experiments in each case he has proved that 

 the rule holds good in the case of some twenty species of gall flies which live on 

 the oak. In every case there are two forms appearing at different times, forming 

 galls with no resemblance to each other, and often resembling each other very 

 little in the perfect insect. He finds that in the species in which this rule ot 

 " alternating generations " holds good the child is never lihe its parents^ either 

 in. form or life history, hut always lihe its grandparents. And with this 

 astounding fact is connected another no less remarkable— that in one of these 

 generations "parthenogenesis" is the invariable method of reproduction -the 

 whole of that generation consisting of female flies alone— whilst in the other 

 generation sexual reproduction takes place in the ordinary way, male and female 

 flies being produced equally from the galls. In a few species, however, this 

 alternating generation does not occur— and "these propagate themselves m an 

 unbroken succession of generations in the female sex "-the galls in this case 

 being all alike. 



An analogous but even more complex case is that of the liver-fluke which 

 caused such widespread destruction among sheep in Wiltshire many years ago. 

 Its life history is given by Dr. Straton as follows :— " The liver-fluke of the sheep 

 gives rise to an active ciliated aquatic embryo, which, after a time, pierces and 

 enters a water-snail to become a passive sporocyst ; from its germ cells redicB are 

 formed within the sporocyst, and after several asexual generations they give 

 rise to minute cercarics which leave the snail and creep up the stalks of grass ; 

 here they become encysted, are eaten, and grow within the sheep to become adult 

 sexual flukes." 



Altogether the book with its appendices containing a synoptical table of gall 

 flies, a bibliography of the subject, a good index, and two folding coloured plates 

 containing excellent figures of forty-two species of oak galls, forms an invaluable 

 and most complete monograph of the subject of which it treats, though the 

 dissertations in the introduction and in the later chapters of the work are not 

 precisely light or easy reading. 



E. H. GODDABD. 



Pheicomenon observed at Kingston Deverill, 1822. 



(From Salisbury and Winchester Journal, May 20th, 1822.) 



" On Monday se'nnight during a thunderstorm and shortly after its commence- 

 ment, a particularly dark and heavy cloud was observed by the inhabitants of 

 Kingston Deverell, on the west of the village ; it sent forth a kind of spout, of 

 a much lighter colour, in an oblique direction towards the earth. After various 

 bendings and contortions like those of the proboscis of an elephant, though no 

 wind was stirring in the lower regions, it extended itself rapidly in length, and 

 as it approached nearer the earth its motion resembled that of a pendulum, but 

 still increasing in celerity of vibration, till the lower end reached the hill on the 

 south-west of the village, between it and Mere, and not above half a mile distant 



