410 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
automatic arrangement preventing a dangerous afflux of blood to tbe 
brain. When it is stimulated, there is an immediate change of blood- 
pressure. But it has also a chemical role ; extracts of hypophysis 
injected into the veins of an animal produce on heart and blood pressure- 
effects identical with those which follow electrical or mechanical stimulus 
of the organ. He compares the action of hypophysine or phosphoro- 
hypophysine with that of iodothyrine from the thyroid. 
Regeneration and Doubling of the Tail in Lizards."' — Dr. G. Tornier 
finds that the Yaranidse and Helodermatidse should be excluded from 
the list which Fr. Werner has given of Lacertilians which do not ex- 
hibit tail-regeneration. He notes that those with heterogeneous scaling 
on the tail are those in which atavistic regeneration might be most 
reasonably expected; yet this is not the case. This is illustrated in 
regard to Pachydactylus capensis in some detail. Most double tails arise 
as the result of a notch on the tail, — a secondary tail growing out from 
the wound. Sometimes, however, they ensue after a bite without any 
notch. The secondary tail is at first at right angles to the axis of the 
wound, but the more abundant nutrition of the side towards the head 
results in bending the extra appendage backwards. 
Studies in Variation.! — Mr. W. J. Moenkhaus has studied the darter 
fishes — Etheostoma caprodes and E. nigrum — from Turkey Lake and 
Tippecanoe Lake, Indiana. In the former species the males are more 
variable than the females (as to rays and spines) in the ratio *507 : *468 ; 
in the latter species the females are more variable than the males in the 
ratio of • 402 : * 454. In both species the individuals differ in the two 
habitats in every structure examined. The differences are apparently 
environmental modifications. Successive broods differ with the varying 
conditions of the year in which they are born. The variations in the 
fins are correlated as follows : — 
(a) When the dorsal spines increase in number, the dorsal rays 
decrease in number. 
( b ) When the anal rays increase, the dorsal spines, the dorsal rays, 
and the sum of the elements in the two dorsals, increase. 
In an abstract of a paper on cave-animals, Prof. C. H. Eigenmann 
criticises current theories, and argues that the Amblyopsidm were not 
swept into the caves, but entered them deliberately, and avoided coming 
out into the light. They were able to establish themselves in caves 
because they were able to do without light, having simjdified eyes and 
highly developed other sense-organs ; they do not possess highly deve- 
loped sense-organs and degenerate eyes because they were accidentally 
swept into caves. A short note is given as to the eyes in Amblyopsis 
and Typhlichthys subterraneus. The degeneration is not the result of 
arrested development or of ontogenic retrogression, nor is it primarily 
due to the cave habitat. The eyes of those species living in the light 
are prophetic of the eyes of those living in the dark. 
Variations and Mutations of the Sparrow’s Egg in America.}: — 
Mr. H. C. Bumpus has compared a large number of sparrow’s eggs from 
* SB. Ges. Nat. Freunde Berlin, 1897, pp. 59-64. 
t Proe. Acad. Sci. Indiana, 1897, pp. 207-31. 
X Biol. Lectures Marine Lab. Woods Holl in 1896, Boston, 1897, pp. 1-15. 
