3882 Arachnida. 



nies, &c. Since this period I have received from Mr. Gosse, and several friends, nu- 

 merous additional subjects to experiment with, which have passed through the trying 

 period of winter with complete success. 



Now as I have heard that other investigators are experimenting with sea-water in 

 these miniature ponds, I am anxious to take the earliest opportunity of communi- 

 cating for their benefit the kind of sea-weeds which I have found most beneficial for 

 the purpose of maintaining the water in this healthy state, so that they may avoid the 

 difficulties I had myself to encounter in first commencing the experiments. The 

 plants which appear to answer best are Ulva latissima and other sea varieties of Ulva, 

 the En terom orphae, and Zostera marina, particularly the latter. The observations 

 which I have been able to make on the numerous inhabitants of my aquarium, I hope 

 to find time to state in detail before long. 



I remain, Yours very truly, 



KOBERT WaRTNGTON. 



E. Newman, Esq. 



Note on the supposed Total Abstinence of a Spider. — Mr. C. R. Bree's observations 

 (Zool.3800) on my communication relative to the "abstinence of a spicier" (Id. 3766), 

 have much pleased me by the candid and philosophical spirit in which they are writ- 

 ten ; and I can assure him that a feeling of the difficulty of accounting physiologically 

 for the so greatly increased bulk of the spider, was my sole inducement to communi- 

 cate the facts of the case, through the medium of the ' Zoologist,' to those who, from 

 their greater and more scientific acquaintance with the physiology of animals, might 

 better than myself offer some solution to the apparent mystery. And, assuming these 

 facts to have been really, and as they appeared to me on close observation at the time 

 to be, correct, to throw out the fair deduction from them, " That the spider existed aud 

 even throve without material sustenance during the time in question," as a point for 

 discussion, to be established or the contrary, according to evidence ; and if establish- 

 ed, then, how far it could be accounted for by the economy or organization of the ani- 

 mal under consideration, or by analogy of other examples of organized life, (supposing 

 in the course of time and observation such analogous examples to arise). I thus re- 

 corded my observations in the pages of the ' Zoologist,' as a " tittle" of evidence to- 

 wards the discussion of this point, and not as " a miracle," nor as set up in opposition 

 to the principle, " Ex nihilo nihil fit ; " and I do not hesitate to say that I can easily 

 and without any violence to that principle conceive it to be established (if indeed it 

 be not already so), that some living creatures can increase to a certain extent, within 

 a limited time, without having during that time received any sustenance, in the same 

 way as an elm tree uprooted, or large branch broken off, in the spring of the year, 

 will, during a certain time afterwards, push forth leaves and small branches. I am 

 perfectly aware that in this case the leaves &c. are the result of the sap contained in 

 the branch at the time of disruption ; but so, in the case of an animal, may the in- 

 crease be the result of prior aliment, enabling it to exist and thrive to a certain point, 

 which passed, it would of necessity die, as also do the leaves &c. of the tree. This 

 was all I intended to convey in my remarks ; and if my words there seemed to con- 

 vey more, it was entirely contrary to my intention. I here also take the opportunity 

 of acknowledging the justness of* the remark by Mr. Browne (Zool. 3845), that " it 



