Mat 17, 1907] 



SCIENCE 



781 



5. Mixed solutions of salts and sugar act 

 more intensely on the Fundulus egg than 

 either constituent would if used alone. A 

 small dose of a salt will give the effect of 

 a much stronger dose if sugar be added to 

 the solution. 



The Degree of Correlation of Certain In- 

 ternal Characters in the Toad: W. E. 

 Kellicott, Womans College, Baltimore. 



Morphogenetic Localization in Aglao- 

 phenia: Raymond Pearl, University of 

 Pennsylvania. 



In the plumularian hydroid Aglao- 

 phenia helleri each fully grown internode 

 of the hydrocladium is divided into three 

 regions by two incomplete, transverse, 

 chitinous septa or ridges. The proximal 

 one of these ridges is at the level of the 

 intrathecal ridge, and the distal one is at 

 the level of the proximal border of the 

 supracalycine nematophores. A study was 

 made of the proportionality of the parts of 

 the internode marked out by these ridges. 

 The general results may be stated as fol- 

 lows: (1) Those proportions of the indi- 

 vidual internode and hydrotheca (= per- 

 son) which involve the localization of 

 points by a process of differentiation in 

 situ after growth is entirely or nearly com- 

 pleted, are maintained in different persons 

 with very much less constancy or precision 

 than are those proportions which depend 

 primarily on growth (as distinct from dif- 

 ferentiation) localizations. (2) There is 

 a distinct correlation between the propor- 

 tionality of the parts and the absolute size 

 of the person in Aglaophenia. In this as 

 in all other cases which have so far been 

 studied quantitatively with reference to 

 this point, the actual facts are in direct 

 contradiction to the fundamental assump- 

 tion made by Driesch in the development 

 of his so-called 'first proof of the autonomy 

 of vital phenomena,' to the effect that the 

 proportionality of the parts of an organism 



is something quite independent of the abso- 

 lute size. 



Correlation as the Basis for Selection in 

 Lepidoptera: H. E. Crampton, Colum- 

 bia University. 



The Blending and Overlap of Instincts: 



Francis H. Herrick, Western Reserve 



University. 



There are many anomalous actions or 

 peculiarities of behavior in wild birds 

 which have not been satisfactorily ex- 

 plained, although certain of them have 

 been long known. Some of the eccentrici- 

 ties of conduct referred to are the follow- 

 ing: (1) Repair of the old nest or the 

 building of a new one at the close of the 

 breeding season; (2) omission of nest 

 building, and dropping of eggs on the 

 ground; (3) leaving young to perish in 

 nest, and starting on migration; (4) offer- 

 ing strings or other objects to young in thfr 

 place of food; (5) building more than one 

 nest including the 'cock nests' of marsh 

 wrens; (6) rebuilding on the same 'site,' 

 producing superimposed nests or nesta of 

 from two to four 'stories' 'to conceal' 

 foreign' bodies, such as the cowbirds' eggs 

 in the nests of vireos and warblers. 



All of these curious actions receive much 

 light, and in most cases are satisfactorily 

 explained by what we shall call the blend- 

 ing or overlapping of instincts. As shown 

 in another paper, the wild bird com- 

 monly passes through a cycle of instincts- 

 which mark the breeding season. This 

 cycle is made up of eight or more terms, 

 which follow in serial order, and some of 

 which are recurrent. Normally the bird 

 passes from center of influence 1 to center- 

 2, 3, and so on, to the end of the cycle. 

 There is little overlap or blending, the bird 

 remaining under the influence of a given 

 instinct or series of instincts, such as nest 

 building, incubation, or feeding the young 

 until its instinct in any given direction haa 



