462 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



The physiological condition of the animal at the time of immersion in 

 the salt solution was found to have an enormous effect on the resisting 

 power. The power of becoming acclimatised to saline solutions is very 

 low in Daphnia. 



The effect of living in a confined volume of water is to diminish the 

 length of the spine and to greatly decrease the power of reproduction. 

 Ultimately the Daphnise die out, and the water can be shown to be in- 

 jurious to fresh Daphnise introduced into it. After a prolonged period 

 the injurious effect passes off, and fresh Daphnise will thrive when intro- 

 duced into the water. The organisms are very sensitive to differences 

 in the mineral constituents of the water in which they are living, a 

 sudden change from New River water to Canterbury water producing a 

 premature weakening of the stock. The interest of these facts is their 

 bearing on the life of the species in natural conditions. 



Fresh-water Entomostraca.* — Mr. D. J. Scourfield, in a general 

 lecture on fresh-water Entomostraca, comments upon the value of Ento- 

 mostraca from the point of view of experimental biology. " Their 

 commonness in all parts of the country, their transparency, the ease 

 with which they can be isolated and reared under all sorts of conditions, 

 . . . mark out the Entomostraca as particularly well fitted for observa- 

 tion in connection with even the most fundamental biological problems 

 of the day." And in other connections there is much that requires to 

 be done : — " We badly want detailed studies on local faunas, on the 

 seasonal distribution and variation of the different species, on the faunas 

 of various types of ponds, on the food of the most abundant forms, and 

 many similar subjects." 



Annulata. 



British Annelids.f — Prof. W. C. M'Intosh has published, as Part II. 

 of his ' Monograph of the British Annelids,' the first instalment of the 

 Polychajta, comprising the families Amphinomiidse to Sigalionidse. The 

 work has been looked forward to for a such a long period, that some dis- 

 appointment will be felt in regard to the small number of families 

 treated ; while the scale on which these are described is^so magnificent 

 that it is to be feared that the remaining volumes can hardly follow 

 rapidly. The volume is lavishly and beautifully illustrated, the ex- 

 ternal form, larval stages, anatomical details, and the specific characters 

 all being represented in the plates. As might be expected, a great part 

 of the volume is taken up by the Polynoidae, which the author separates 

 as a family from the Aphroditidae. The British forms are arranged in 

 fourteen genera, but the British area is taken in the extended sense, as 

 stretching from the Faroe Channel to the Channel Islands, and beyond 

 the 100 fathoms line on the west, which greatly increases our toll of 

 species. The volume obviously represents so long and arduous a period 

 of preparation, that it is perhaps ungracious to note that the absence of 

 even a 1st of genera and species makes it somewhat difficult to use. This, 

 however, only accentuates the eagerness with which the following volumes 

 with tables and indices will be looked for. 



* Proc. South London Entomol. and Nat. Hist. Soc, 1899, pp. 28-30. 

 t ' A Monograph of the British Annelids,' Part II., Ray Society, 1900, pp. 215-442 

 (10 pis. aDd 33 tigs.). 



