ZOOLOaY AND BOTANY, MICROSCOPY, ETC. 33 



Cyclops strenuus, four Amphibians, and a wild duck. Tlie fauna is 

 marked as a whole by the capacity of its components for lying quiescent 

 in the mud or the like during unpropitious conditions, such as drought. 



J. A. T. 



Colours of Reef-flshes. — W. H. Loxgley {Proc. Amer. Soc. Zool. 

 in Anat. Record, 1919, 15, 350-1). West Indian and Hawaiian reef- 

 fishes are protected by general colour and pattern. A new observation 

 records the fact that some change their coloration as they rise vertically, 

 leaving the bottom and its influence. This is adaptive, like the change 

 of colour associated with horizontal movement. " Nuptial coloration " 

 may be sometinies an index of changed location at that period. 



J . ix. J- • 



Reaction of Fishes to H-ions. — Y. E. Shelfoed {Proc. Amer. Soc. 

 Zool. in Anat. Record, 1919, 15, 347). Experiments show thatmany 

 marine fishes are exceedingly sensitive to minute differences in the 

 concentration of hydrogen ions. The Pacific herring reacts negatively 

 to 0*8 part per million of sulphurous acid (H2SO3) in a manner which 

 indicates an ability to distinguish 0*6 part per million. In this case 

 the difference in H-ion concentration is very slight, probably too slight 

 to be distinguished. Reactions to other chemicals indicate that small 

 amounts of other ions may predominate over small H-ion concentration. 



Are there Varieties of Eel ?— 0. Nordqvist {Ar¥iv Zool., 1917, 

 11, No. 6, 1-22). The application of biometric methods to a large 

 body of measurements of the common eel {Angudla angidlla) shows 

 that there are considerable differences in the proportions of the body in 

 the two sexes and at different ages. But as regards the existence of 

 narrow-headed and broad-headed varieties the author's results are 

 negative. He points out, however, why he is not prepared as yet to 

 give an answer in the negative. J- A. T. 



Pelvic Structure and Burrowing Habits. — Royal Norton 

 Chapjian {Amer. Journ. Anat., 1919, 25, 185-219, 5 pis.). In moles 

 there are horizontal pelves firmly co-ossified to the vertebral column, 

 the ventral margins of the pubes are horizontal and diverge posteriorly, 

 and there is no pubic symphysis. In gophers the same holds, but the 

 symphysis is present in the males and some females. In the marsupial 

 mole the pelvic bones are co-ossified firmly to the vertebral column, the 

 pelvis is horizontal, and the symphysis is greatly reduced. A horizontal 

 pelvis firmly fused to the vertebral column, and the reduction or absence 

 of symphysis, may be correlated with the mechanical force exerted by 

 the hind limbs in propelling the body in continuous burrowing. The 

 horizontal position of the pelvis transmits the locomotive force exerted 

 by the hind limbs along a straight line from the articulation of the 

 limbs to the anterior part of the body. In a similar way the author 

 interprets the reduction of the symphysis, its retention in the pocket 

 gophers, the broad and narrow pelves, the crossing of the rectus abdo- 

 minis muscles, and so on. From a number of variations in each group 



D 



