642 REPORT— 1889. 



' are the progeny of the original 129 insects referred to above, which will give 

 some idea of the rapidity with which these insects breed. Several of the orange- 

 trees at Mr. Wolfskills have been almost entirely cleared of the Iceryas by these 

 ladybirds, and on the other trees their numbers are becoming rapidly lessened 

 through the persistent attacks of their merciless foes.' 



Besides the 129 specimens referred to above, two later consignments were 

 received. One of these arrived February 21, and consisted of 35 specimens, which 

 were colonised on an orange-tree in the San Gabriel Valley. A much larger 

 consignment, containing about 350 specimens in different stages, was received 

 Marcli 20, some of which were also colonised at the same place, while the re- 

 mainder were placed in another grove. 



The increase of the Lestophonus is more slow. Speaking of these importations 

 in my last report (p. 90), I remarked : * We fully expect to learn of the increase 

 and rapid spread of this new introduction as well as of some of the other pre- 

 daceous species which have been introduced, and to find that in a comparatively 

 few years the orange groves of Southern California will be kept measurably free of 

 the pernicious fluted scale without so great an effort on the part of the growers or 

 so great expense in destroying it. That nature wiU, with the new conditions 

 induced by these importations, come to the relief of the fruit-grower, and that this 

 interesting experiment will result in the ultimate saving of untold millions to the 

 people of the Pacific coast, is our sincere belief, which we hope to live to see 

 verified. Not that we expect the Icerya to be ever entirely exterminated, but it 

 will be kept under subjection so as to be comparatively harmless, as it is in its 

 native country.' 



These predictions are in a fair way of realisation, and the instance is of 

 sufficient scientific and economic interest to justify the sending to the British 

 Association of this abstract of a fuller note which I have sent to the American 

 Association on the subject. 



6. The Uses of the Testacece or Concliiferous Molluscs in Nature, Science, and 



the Arts. By B. "W. Gibsone. 



7. On the work done at the Laboratory of the Marine Biological Association 

 in the past year. By G. C. Bourne, M.A. 



8. The Morphology of the Antipatharia. By G. Brook, F.L.8. 



9. Some Bemarks on the Functional Equivalency of certain Parts of Limbs. 

 By Professor R. J. Anderson, M.A., M.D. 



Professor Owen has discussed the serial homology of parts of limbs. His 

 opinions are generally accepted. The analogy of certain structures is fully ex- 

 plained by the same anatomist, who takes care to show that things that are 

 analogous are not necessarily homologous. The close relationship of function and 

 structure is well seen in joints, and a classification according to function in human 

 anatomy corresponds very nearly to a classification according to structure. I think 

 an attempt may be made to determine the functional equivalency of parts of the 

 fore and hind limbs in mammals. 



1. By ' functional equivalency ' I mean the equivalence of the actions of certain 

 parts of limbs in their bearing on the animal as a whole. The front limb of the 

 horse is elevated by a backward bend at the elbow, whilst the posterior is elevated 

 by a bend back at the heel. The elbow and ankle may then be regarded as 

 ' functional equivalents.' The functional equivalency is less apparent in some 

 animals than in others. Many anatomists have made measurements of the limbs 

 and their segments in many animals. I have done the same, and submit a list of 

 measurements in difierent breeds of dogs I have also compared. 



