SCIENCE. 



[Vol. VI.) No. 126, 



decim has several very distinct and variable notes. 

 He has probably been misled by the abnormal con- 

 dition of things the present year in the District of 

 Columbia, where the English sparrow has so pre- 

 vented the full maturity of the males, and so deci- 

 mated their ranks, that the more characteristic 

 noises, and those most apt to be recollected, have 

 scarcely been heard. This has been a common re- 

 mark among entomologists, who recollected former 

 visitations in other parts of the country. 



Finally, Professor Ward will convince no one that 

 I was ever guilty of speaking of the note of Cicada 

 pruinosa as ' precisely like ' that of C. septendecim, 

 though the mature and louder note of the latter much 

 more nearly resembles that of the former than he 

 seems to imagine. C. V. Riley. 



Washington, D.C., June 17. 



Periodical cicada in Massachusetts, 



Among the localities given by the earlier writers for 

 the present septendecim brood of the periodical cica- 

 da, are Fall River and the south-eastern portion of 

 Massachusetts. These need confirmation ; as, so far, 

 no reports have been received from Massachusetts the 

 present year. There is a brood which appears at 

 Fall River one year later. I shall be glad to get con- 

 firmation either of the absence or presence of the in- 

 sect the present year from the readers of Science in 

 south-eastern Massachusetts. C. V. Riley. 



Washington, D.C. 



Height of land in Connecticut. 



The ninth and last edition of the 'Encyclopaedia 

 Britannica ' has the statement that there is no land 

 in Connecticut ' above a thousand feet in elevation.' 

 Statements equivalent to this will be found also in 

 ' Appletons' American cyclopaedia' and in ' Johnson's 

 cyclopaedia.' A survey by an engineer, Mr. G. M. 

 Bradford, in 187o, which was based on the survey of 

 the Connecticut western railroad, gives the heights 

 of several points in the north-western part of this 

 state, and these results cannot be much in error. I 

 am indebted to Mr. Henry Norton of Goshen, Conn., 

 for the communication of these heights. It will be 

 remembered that Salisbury is the north-western town 

 of the state, and that east of it, joining Massachu- 

 setts, are Canaan and Norfolk: Goshen joins Norfolk 

 on the south. The following are some of the heights 

 above sea-level : — 



Feet. 



Ivy Mount (Goshen) 1,642 



Haystacli Mount (Norfolli) 1,672 



Bald Mount (Norfolk) 1,770 



Bradford Mount (Canaan) 1,910 



Bear Mount (Salisbury) 2,100 



Brace Mount (Salisbury) 2,.'i00 



It may be thought hardly worth while to dispute 

 any statement made in a cyclopaedia; but, having 

 been born and reared among the beautiful hills of 

 Connecticut, I dislike to see them diminished to one- 

 half their height, even by such a ponderous authority 

 as the 'Encyclopaedia Britannica.' 



Asaph Hall. 



June 27. 



The ginkgo-tree. 



In Science, No. 124, Mr. L. F. Ward states that the 

 Frankfort, Ky., ginkgo-trees are the only ones known 

 to him in the United States that have borne fruit. 

 Permit me to say that a group of these trees in Cen- 

 tral Park, New- York City, have borne fruit to my 

 knowledge for the past six years, and that in great 

 abundance. R. P. Whitfield. 



Amer. mus. nat. hist., 

 June 24. 



THE FORMATIVE FORCE OF 

 ORGANISMS. 



The assertion is safe, that the majority of 

 biologists incline at present to explain the 

 forming of an organism out of its germ upon 

 mechanical principles. The prevalent concep- 

 tion is, that the forces of the ovum are so dis- 

 posed that the evolution of the adult organism 

 is the mechanical result of the predetermined 

 interplay of those forces. The object of the 

 present article is to point out that this concep- 

 tion is inadequate, and must be at least sup- 

 plemented, if not replaced, by another view ; 

 namely, that the formative force is a generally 

 diffused tendency, so that all parts inherently 

 tend to complete, b}^ their own growth and 

 modification, the whole organism, — a fact 

 which finds a legitimate hypothetical expres- 

 sion in Darwin's doctrine of pangenesis. The 

 nature of the view here advanced will become 

 clearer upon consideration of the evidence 

 upon which it is based, and which is adduced 

 below. The evidence that the formative force 

 is difi'used through all parts falls under three 

 heads : 1 . The process of regeneration in uni- 

 cellular and multicellular bionts ; 2. The phe- 

 nomena of the duplication of parts ; 3. All 

 forms of organic reproduction. Let us briefly 

 consider these categories. 



1. Regeneration. All living organisms have 

 to a greater or less degree the ability to repair 

 injuries : indeed, we must regard the power 

 of regeneration as coextensive with life, but 

 the capacit}' varies enormously in the different 

 species. In man the power is very small, 

 though more extensive than is generally re- 

 alized. Among annelids are species the indi- 

 viduals of which may be divided in two, and 

 each piece can regenerate all that is needed 

 to render it a complete worm. We some- 

 times see a small fragment of a plant, a single 

 switch of a willow for instance, regenerate an 

 entire tree, — roots, trunk, branches, leaves, 

 flowers, and all. In the last instance a few 

 cells possess a latent formative force, which 

 we recognize by its effects, but cannot explain. 

 We perceive, therefore, that each individual 

 has, as it were, a scheme or plan of its organ- 

 ization to which it strives to conform. As 

 long as it actually does so, the cells perform 

 their routine fLuictions ; but when an injury 

 destroys or removes some portion, then the 

 remaining cells strive to conform again to the 

 complete scheme, and to add the missing frag- 

 ment. The act of regeneration of lost parts 

 strikes the imagination almost as an intelligent 

 pursuit by the tissues of an ideal purpose. 



Our knowledge of the regenerating power 



