HARDWICKE'S SCIENCE-GOSSIP. 



a basic material which combines with the phosphoric 

 acid formed by the oxidation of the phosphorus con- 

 tained in pig-iron made from the most abundant and 

 cheapest iron ores. The phosphate thus obtained 

 should be useful as a manure, and M. Fleischer has 

 for some time past been working on the subject to 

 determine whether such theoretical anticipation is 

 verified in practice. The compound in question 

 fuses readily, and, being lighter than the molten iron, 

 floats on the top as a liquid cinder or slag. M. 

 Fleischer, as a mean of several analyses, finds that it 

 contains in ioo parts 17*5 of phosphoric acid ; 48 29 

 to 49/6 of lime ; 47 to 4^9 of magnesia, with small 

 quantities of iron, alumina, manganese, free sulphur, 

 sulphuric acid and silicic acid. Numerous experi- 

 ments made at various experimental stations show 

 very good results when this slag, ground to pow- 

 der, was tried against other manures, and, although 

 M. Fleischer thinks it premature to give a definite 

 opinion, he believes that there is a good future for 

 this material. Deep cultivation and mixture with 

 the soil for tillage, and early top-dressing in meadow 

 land, is recommended. 



The subject is of considerable practical importance, 

 as the quantities obtained are very great : many tons 

 per day from every pair of converters in full work. 



A GROUP OF ROTIFERS. 



Notes on the Genus Euchlanis. 



PERHAPS no class of animals have been greater 

 favourites with microscopists than the Rotifera ; 

 their minuteness, the beauty and variety of their 

 form, their liveliness, the remarkable transparency of 

 their integument, their ubiquity, and the many un- 

 solved problems in regard to their organization and 

 life-history, have always exercised a charm equalled 

 perhaps by no other class in the animal kingdom. 

 Every possessor of a microscope has been more or less 

 of an enthusiast, and has never tired of showing the 

 wonderful "wheel-animalcules" to a circle of his 

 admiring friends. This being the case, it is some- 

 what disappointing that so little is done towards 

 elucidating the organization, or recording the habits 

 and peculiarities of these remarkable animals. Our 

 magazines, whether devoted to general natural 

 history, or specially to microscopical subjects, rarely 

 contain any articles or notes, either on this class or 

 the more humble Infusoria. This has often been a 

 matter of considerable surprise to me, especially 

 when one calls to mind their wide distribution, so 

 that no one is so unfavourably situated as not to be 

 able, by carefully working his district, to procure, I 

 believe, at least 50 per cent, of the species known to 

 science. Considering the amount of activity being 

 displayed in other branches of microscopical know- 

 ledge, and the further fact, that numerous natural 



history societies have been formed in various parts 

 of the country, that surprise is certainly not lessened, 

 but intensified. It is to be feared that too many of 

 the possessors of microscopes apply them, in the 

 words of the late lamented Dr. Carpenter, "in such 

 desultory observations as are of no service whatever 

 to science, and very little to the mind of the ob- 

 server." It is a fact that all the advance that has 

 been made in our knowledge of these animals in 

 recent years has been due to a very limited number 

 of earnest workers — a number which probably might 

 be counted on the fingers of one hand. We may not 

 all, by philosophic induction, comprehensive research, 

 and enlarged generalisation, be able to discover " the 

 grand and harmonious plan upon which all organic 

 creation is believed to have been formed ; " we may 

 not either by nature or education be competent to 

 discuss the zoological position of the Rotifera — whether 

 they have most affinity with the worms, the crabs, or 

 the insects ; but the most humbly endowed amongst 

 us, if not an absolute idiot, can become a careful ob- 

 server of facts, and it is upon these only that a correct 

 classification can be based. Holding these opinions, 

 and thinking I might interest and possibly assist 

 some of your readers, I have ventured to send these 

 notes on the genus Euchlanis, family Euchlanidota. 

 This family is one of the largest, containing, according 

 to our present method of classification, eleven genera, 

 and is second only to the family Hydatinrea. It is, 

 however, more than probable that this number will 

 be reduced, or at least that there will be a rearrange- 

 ment ; for instance, the three genera Metopidia, 

 Lepadella, and Squamella, separated by Ehrenberg 

 on account of supposed differences in the number of 

 their eye-specks, were pointed out years ago by 

 Dujardin as forming a very natural single genus. 

 While not prepared to go so far, I may say that I 

 have never come across any Rotifer with more than 

 two eyes. My friend Mr. F. Sutcliffe, of Bacup, an 

 experienced microscopist and careful observer, with 

 whom I frequently work, confirms me in this, and 

 further informs me that he has frequently found in 

 the same gathering specimens otherwise indistinguish- 

 able with two well-developed eye-specks, and others 

 in which these were quite invisible — an experience 

 which is in keeping with my own. Dujardin also 

 does not admit the genus Monostyla, but places the 

 four species comprising it in the genus Euchlanis- 

 The only species of this genus I have been fortunate 

 enough to see is one which, from my description and 

 drawings in the "Microscopical News" of June, 

 1884, Mr. Gosse identified as his Monostyla bulla ; 

 and it is confirmatory of Dujardin's opinion, that I 

 had myself noticed its many points of agreement with 

 other Rotifers I figured in the same number, not then 

 identified, but since clearly proved to be a species of 

 Euchlanis. On the other hand, the mastax of all 

 my Euchlanes are of the brachionsean type, and vary 

 very little indeed, except in size, while that of M. 



