December 22, 1898J 



NA TURE 



-ness). It will be seen, therefore, that with regard to frequency 

 of meteors this later portion of the shower was not to be com- 

 pared with that witnessed before midnight. Twelve meteors, 

 including one of the first magnitude and two even brighter, 

 were mapped between ilh. 30ni. and I3h. on the night of the 

 9th ; -four of these were Geminids. W. E. Beslev. 



70 Vincent Square, S.W., December i6. 



, Slug following a Closed Trail. 



My attention was drawn a few days ago lo a brown slug, 

 about 2^ inches long, which had made for itself a closed iri- 

 -descent track on the concrete flooring of 

 'a conservatory. I could not find at what 

 ''point it had got on to the curve, which 

 ■ran at one end into a damp part of the 

 concrete, but, in four hours from the time 

 I first saw the slug, it had made three 

 'complete circuits and two-thirds of a 

 fourth, always keeping the whole of its 

 body on the trail. The latter, of a uni- 

 form breadth of 3/16 inch, varied consider- 

 ' ably in curvature, but nowhere presented 

 any very sharp corners, and measured, 

 roughly, forty inches round. Though the 

 rale of progression was sufficiently slow, 

 the slug rested on the track for seven hours, 

 after which, thinking it dead, I touched 

 it and found it had not quite dried up. 

 Indeed, without elongating its body, it 

 began to move and laboriously shifted its 

 position by about an inch. There it re- 

 mained (the time being then 10 p.m.), 

 waiting, perhaps, for the influence of a 

 more humid atmosphere, for morning found 

 it moist and healthy, breakfasting more 

 than a yard from the near and damp end 

 of the track, which it must have reached 

 by completing the fourth circuit, as there 

 was no trail other than the closed one 

 alluded to. If slugs are in the habit of 

 following old trails, it does not appear that 

 the present specimen had any previous ex- 

 perience of a re-entrant path, but that it 

 depended solely on ocular intelligence of 

 the path in advance. 



Vincent Daniel. 

 151 Crwys Road, Cardiff, December 13. 



Animals Feeding on Poisonous 

 Plants as Food. 



ArRoi'OS of the various instances quoted 

 of animals feeding on poisonous plants, it 

 may be of interest to mention that in this 

 part of India (the North-west Provinces), 

 goats frequently eat, without any ill effect, 

 the leaves and green stems of the " Akaua" 

 or " .Madar " {Asc/epias or Calotropis 

 giganlca), the milky juice of which is an 

 acrid poison for human beings, and is 

 frequently used as such in infanticide cases. 



Ch.^S. a. SlLBERRAD. 



Muttra, India, November iS. 



THE FUMIGATION OF 

 TREES.^ 

 HE San Jose Scale was first dis- 

 covered by Prof. J. H. Corn- 

 stock, near San Jose, California, in 

 1879, and was named by him Aspidiotus pcriiiciosus. 

 It has been found in various parts of the world, and its 

 original habitat has not vet been ascertained with 

 certainty, but is conjectured to be Japan. In 1893 it was 



1 " Report on the San Jose Scale in Maryland, and Remedies for its 

 Suppress.on and Control." By W. G. Johnson A.M., Emomo logi. 



first discovered in the Eastern States, having been intro- 

 duced about si.\ years before with some infested plum- 

 trees from California, in'the attempt to obtain an improved 

 plum which should be proof against the attacks of the 

 plum-weevil ; but this laudable object proved the means 

 of introducing a much worse pest into the Eastern States. 

 According to the pamphlet before us, it has now been 

 introduced into no less than thirty-three States, besides 

 Canada and British Columbia, chiefly from the centre of 

 infection in New Jersey. The State of Maryland is badly 

 infested, large orchards of plum, pear, peach, cherry, &c.,. 



Jl 



NO. I 52 I, VOL. 59] 



haviiig been almost entirely destroyed by it in some 

 localities. The insect attacks trees and plants in a 

 similar manner to other Coiciiiiu; attacking a great \ ariety 

 of plants, and spreading over leaves, trunk, branches, and 

 fruit indiscriminately. The effects of various remedies- 

 are discussed by Prof Johnson, spraying with whale-oil 

 soap, and fumigating with hydrocyanic acid gas, appearing 

 to be the most satisfactory and efficacious remedies^ 



