CLASSIFICATION OF ANIMAL PREPARATIONS. 



411 



develops from every part of its surface single, short, thick 

 tapering tubes, within which, in some cases, a spiral fibre is 

 loosely coiled, whilst in others the place of the spiral fibre 

 is supplied by distant rings. The seeds of the following 

 plants should be selected and treated in the manner above 

 described : — 



Acanthodium spicatum, 



Blepharis 



Casuarina, 



CoUomia grandifolia, 



linearis, 



Phaylopsis glutinosa, 



Ruellia fonnosa, 

 Salvia pratensis, 

 Salvia 



ANIMAL TISSUES. 



Preparations of animal structures are obtained in a variety 

 of ways ; but, more or less, dissection wiU be found necessary 

 in almost every case. The subjoined hsts wiU afford a few of 

 the best examples of the different kinds that may be procured 

 from the various classes of animals. 



Siliceous Skeletons of recent and fossil Infusoria. — These may 

 be obtained from a variety of sources, and as they are capable 

 of resisting the action of strong acids, the method described at 

 page 397 will be found necessary in aU cases. They may be 

 mounted in balsam or in fluid; the very delicate kinds for 

 test objects are, however, generally mounted dry, between two 

 pieces of thin glass. The following are the localities in which 

 the most remarkable species have been foimd : — 



Recent Infusoria. 



