490 



SCIENCE 



[N. S. Vol. XXVII. No. 691 



coast of France, Spain, and the Nether- 

 lands with 11; and then Scandinavia with 

 10 species. From Oceania have been col- 

 lected 10 or 11 species which are known 

 also in Bermuda, from the Red sea 7, and 

 from the Indian Ocean 5. Six of the Ber- 

 muda species are essentially world wide in 

 their distribution. 



Individual Action of the Ganglia- of the 

 Razor-shell Clam, Ensis directiLS: Gil- 

 man A. Dkew, University of Maine. 

 Although accessory ganglia are reported 

 to occur on the cerebro-visceral connectives 

 of Solen, serial sections and dissections 

 have not shown them in this form. 



Both cerebral and visceral ganglia are 

 able to receive sensory impulses and to send 

 out motor impulses, when isolated from 

 other ganglia. When the cerebro-pedal 

 connectives are cut, stimulation of the sur- 

 face of the foot causes only local contrac- 

 tions. The foot as a whole does not re- 

 spond. This seems to indicate either that 

 the pedal ganglia have no motor cells or 

 that the sensory neurons from the foot are 

 continued through the pedal ganglia to 

 the cerebral without endings or collaterals. 

 The latter arrangement seems more prob- 

 able for the following reasons: (1) Many 

 ganglion cells are present in the pedal 

 ganglia and sensory cells alone would 

 hardly be expected in such a muscular 

 organ as the foot. (2) Cutting the 

 cerebro-pedal connectives causes tetanic 

 contractions of the whole foot and not 

 single twitches. (3) With both cei'ebro- 

 pedal connectives cut, stimulation of one 

 connective causes complete contraction of 

 the whole foot, an action that is very dif- 

 ferent from that obtained by stimulating 

 the pedal nerves of one side after they have 

 been separated from the ganglia. This 

 seems to show that the stimulus is received 

 by the ganglia and referred by association 



fibers to the motor cells that control the 

 movements of the entire foot. 



The Physiology of the Stomach of Higher 

 Crustacea: Leonard W. Williams. 

 The cardiac canals described by the au- 

 thor in the lobster's stomach have been 

 found also in Astacus, Cambarus, Ne- 

 throps, Sqidlla and in the fiddler, common, 

 spider and hermit crabs. The lower canal 

 alone exists in the isopod Idothea and in 

 the amphipod Talorchestia. The general 

 occurrence of these canals in higher Crus- 

 tacea, as well as in larval lobsters, indi- 

 cates their physiological importance. It is 

 believed that they bring to the pyloric 

 cushions or pads the nutrient fluid and 

 suspended particles which are freed by the 

 gastric mill and which enter the canals be- 

 tween the closely interlocking bristles of 

 the side and floor of the cardiac sac. In 

 the pyloric cushions, the fluid is again 

 filtered and then enters the large digestive 

 gland ("liver"), while the particles caught 

 in the cushion are carried backward into 

 the hind gut. 



Relation of Instinct to Intelligence in 

 Birds: Francis H. Herrick, Western 

 Reserve University. 



The Breeding Habits of the Loggerhead 

 Turtle and Some Early Instincts of the 

 Young: Davenport Hooker, Tale Uni- 

 versity. 



The breeding season of the loggerhead 

 turtle lasts through the months of April, 

 May and June. There seems to be basis 

 for belief that two nests are laid in a season 

 by each female. The number of eggs laid 

 is approximately one hundred. The period 

 of incubation lasts about fifty days. 



Experimentation on the newly-hatched 

 young gave results which may be briefly 

 stated as follows: (1) They have an in- 

 herent tendency to descend inclines and 

 are positively phototropic. Both tenden- 



