1895.] MICROSCOPICAL JOURNAL. 381 



Then there is another group in which the sponges are 

 the most common. In this the skeleton is more or less 

 extensively composed of siliceous needles or " spicules " 

 of various forms. They can be mounted entire to show 

 the sponge as it lives, or thej can be pasted, but not too 

 long, experience will show how long, and the spicules 

 mounted after drying in gum thus. These spicules may 

 be imbedded in various ways in a reticulated fibrous 

 skeleton of spongian ; or the horny material may be 

 greatly reduced so that the skeleton-fibre consists 

 essentially of minute flinty needles. There is a third 

 group in which the skeleton is destitute of horny matter, 

 but spicules are present. They may be fused with 

 one another into a continuous framework, or may be so 

 interlocked by their ends as to produce practical rigidity, 

 or may be simply held in position by the fleshy substance 

 of the sponge. In both this group and the preceding, in 

 addition to the spicules of the proper skeleton, there are 

 generally developed in the mesoderm numerous still 

 more minute microscopic needles of flint, which are known 

 as " flesh spicules;" and, lastly, there is a group of sponges 

 in which the skeleton is wholly made up of spicules of 

 carbonate of lime. In these of course in mounting them 

 acids must not be used as they will dissolve the spicules. 

 They must be cleaned by boiling in caustic potash or 

 soda, washed in water and mounted in gum thus. 



The Penetration of Microbes into the Blood. — M. No- 

 card reported at a recent meeting of the Society of Biology 

 Paris, experiments by which he has been able to demonstrate 

 that microbes are capable of entering the blood through the 

 alimentary canal. He lound that, while the blood is usually 

 sterile after an ordinary meal, a few microbes being found in 

 the blood, after a meal containing a considerable quantity of 

 fat microbes were found very abundant. His theory is tiuit mi- 

 crobes are conveyed into the bf)od by the small fat globules, 

 which are taken up by the lacteals. — Druggists Circular. 



