124 



♦ KNOWLEDGE ♦ 



[Aug. 24, 1883. 



The ciliated cells of the interior of the body cavity, now 

 called a venlriculus, draw in water through the pores or inlia- 

 lent apertures, and the currents are discharged through the 

 large osculum (Fig. 11, //). In this way food is brought to 

 every part of the animal organisation suspended in the 

 water. The currents, of course, are produced by the 

 lashing of the cilia within. 



Fig. 12. — Grantia compressa, a calcareous sponge. A. Flagelljito 

 monadiform cell ; /, flagellutn ; a, collar ; c, contractile vacuole ; 

 n, nucleus. B. Amoeboid cell ; p, pseudopodium. C. Trii'adiate 

 spicule. (After Carter.) 



If now we analyse the body microscopically in detail, 

 we find that the ciliated cells, or, as they are now called, endo- 

 dermal cells, are provided with a collar-like armature, from 

 the centre of which the cilium projects, and that the entire 

 cell, when isolated (Fig. 1:.', A), bears a strong resemblance 

 to some of the collared monads amongst the Hagellated 

 Infusoria. It is said that when these cells are fed with 

 coloured particles, such as carmine or Bismarck brown,* 

 the material enters between the cilium and the collar, and 

 thence finds its way into the body of the cell. The outer 

 layer of cells, now denominated the ectoderm, which, as we 

 have already stated, becomes fused into a syncytium, is 

 seen to be made up of little particles resembling Anuebce 

 (Fig. 12, B), provided with nuclei and contracting vesicles. 

 Lieberkiihn has stated that whilst they seem to be com- 

 pletely fused, they are not so in reality, because, in the 

 case of Spongilla, he separated the cells most readily 

 by applying a heat just sufficient to cause proto- 

 plasmic coagulation. But this is no argument in favour 

 of their being independent organisms merely asso- 

 ciated together, because such a heat would probably be 

 sufficient to dissolve the interstitial cement which held the 

 cells together. Besides, it is a fact well-known to all his- 

 tological workers, that almost every tissue is capable of 

 dissociation by means of heat, chemical reagents, or fer- 

 ments ; so that the theory of mere coherence through 

 vitality here must fall to the ground. The cells of the 

 sponge, however, are largely endowed with an independent 

 existence ; thus, if two SpoufjiJhr are brought together, 

 they gradually coalesce to form a single sponge ; or, con- 

 versely, if a living sponge is cut into pieces, each piece so 

 detached is capable of living and growing. In fact, these 

 occurrences have been taken advantage of by Dr. Oscar 

 Schmidt in his experiments on sponge life, and are now 

 being widely adopted in the commercial fisheries of the 

 Adriatic. 



The ectodermal cells of the adult sponge are also said to 

 be capable of ingesting food by themselves ; but it is more 

 probable that they derive their nutriment secondarily 

 through the pabulum collected by the endodermic cells. 



When a sponge such as that just described developes 



* It is best to nse Bismarck brown or Vesuvin, as the living 

 organisms become stained without being killed. Carmine usually 

 paralyses delicate organisms. — J. E. A. 



spicules of an organic material impregnated with carbonate 

 of lime, the spicules are usually tri-radiate (Fig. 12, C), and 

 the sponge is called a calcareous sponge. The Ascetta 

 primordialis of Haeckel is a simple form of sponge of this 

 kind ; in it we find a flask-shaped body turned upside- 

 down, the neck of the flask is fixed to the substratum, 

 whilst its base remains patent as the osculum. Its walls 

 are composed of only two layers of cells, the ectoderm and 

 endoderm ; and in the former, which is in form of a syncy- 

 tium, the tri-radiate spicules of carbonate of lime are 

 scattered. These spicules are concentrically deposited, and 

 form a firm basis upon which the superstructure is sup- 

 ported. Some of the endodermal cells become converted 

 into the mother cells of the spermatozoa ; whilst other cells 

 of either layer are changed into ova, and thus we are 

 brought to the commencement of the cycle of changes 

 described. 



Me.ssrs. R. Clay, Sons, &. Tavu)r, of Bread-street Hill, 

 E.G., have purchased the Pictorial World, with the intention 

 of carrying it on under such new and improved arrange- 

 ments as are likely to secure the success which its present 

 large circulation and popularity ought to piit beyond a 

 doubt. 



Thunderstorm. — Telegrams from Geneva, dated the 

 15th inst., speak of a very violent thunderstorm as having 

 occurred in the Jura on the morning of that date. Several 

 houses are reported to have been struck, and villages set 

 on fire, whilst the telegraphic and telephonic service was 

 deranged. The centre of the storm seems to have been 

 about Neuchatel, where for some twenty minutes the sky 

 is reported to have been in a continual blaze. 



Telephone Wires and the Public. — On Saturday week, 

 in the City of London Court, before Mr. Commissioner 

 Kerr, an application was made by Mr. G. Kebbell, solicitor, 

 Seething-lane, on behalf of Mr. German, the freeholder of 

 land at Bow, for an order by way of injunction restraining 

 the United Telephone Company and directing them to 

 remove certain posts which they had erected on his property, 

 as well as the wires suspended therefrom. The pro- 

 ceedings, as given in the daily press, were somewhat amus- 

 ing, as will lie seen from the following report : — Mr. Scott, 

 barrister, for the defendant company, contended that they 

 had obtained leave from the lessees of certain parts of the 

 land to erect the posts. Mr. Kebbell denied this, and said 

 that the posts were really placed on the plaintift''s land, 

 over which the lessees had a right of way, and that the wires 

 were beyond doubt suspended across the land in question, 

 which was unoccupied. Mr. Scott : Your Honour knows 

 that it lias become a custom for telephone companies to 

 place their wires from house to house, and few people 

 object, as it is a matter of public convenience. His 

 Honour : That cannot give the companies a right to put 

 their wires across any man's land. The law is that an 

 owner is entitled to tlie enjoyment of everything between 

 his land and the heavens. Why does not the plaintiff cut 

 the wires ? Mr. Kebbell : That is just the difficulty. We 

 are afraid tliat if we did so the wires would fall on other 

 people's land and endanger life. His Honour : But you 

 would not be liable to a charge of manslaughter. Mr. 

 Kebbell : Without discussing my client's legal position, I 

 could not allow him to take a course by which life might 

 be imperilled. His Honour : No doubt. The matter had 

 better stand over till the hearing, and I promise that you 

 shall not be prejudiced by the delay. The case was ac- 

 cordingly adjourned. 



