102 The Scottish Naturalist. 



As in the geological department, the back of the case bears a 

 placard, indicating the nature of the specimens in the tray. In 

 the zoological department these placards give the name and 

 essential characters of each sub-division. In the trays themselves 

 are placed narrow bands of paper, crossing from one side to the 

 other, and indicating the names, and the essential characters of 

 the various classes, orders, or families. Thus in the tray devoted 

 to Protozoa, we have three such bands, being one to each of the 

 classes Rhizopoda, Gregarinida, and Infusoria. Each specimen, 

 model, or drawing is also labelled with its name, and any other 

 information that may seem desirable. 



All the sub-divisions of the Invertebrata are treated in the same 

 way, and, wherever possible, actual specimens are given. In such 

 a sub-kingdom as Cozlenterata, many of the animals in which are 

 not possessed of hard parts, and which are also difficult to preserve 

 so as to give any true idea of their structure and appearance, 

 models have been largely resorted to. Fortunately, the beautiful 

 glass models prepared by Blaschka of Dresden, which illustrate 

 not only the external appearance of the animals, but also, in many 

 cases, their internal structure, can be purchased at a moderate 

 price. 



Here it may be well to observe that in arranging such a collec- 

 tion as the one we are describing, it will be found a very great 

 advantage to have a narrow upright case between each two table- 

 cases, furnished with glass shelves, on which to place the prepara- 

 tions that must be preserved in fluid in jars. Experience proves 

 that it is impossible to display to any advantage such preparations 

 in a table-case, and that for purposes of study, the latter must be 

 supplemented with the upright case. 



At the commencement of each sub-kingdom is placed a diagram 

 of its essential type of structure ; and where necessary this diagram 

 is supplemented by others. 



The sub-kingdoms Echinodermata and Venues are illustrated 

 in the same manner as the Ceelenierata, by means of actual speci- 

 mens, fluid preparations, models, and drawings ; and the life- 

 history and anatomy of several species are demonstrated. 



To the Arthropoda are allotted, as has been said above, six 

 trays. Of these the Insecta occupy three, not that they are con- 

 sidered to be of so great relative importance, but because, from the 

 inland situation of the Museum, they form a very large part of 

 the Invertebrata of the surrounding district. Hence it has been 

 considered advisable to show specimens to illustrate all the chief 

 orders. Preparations illustrate the structure of certain selected 

 types, and also their metamorphoses, whether complete or incom- 

 plete. The other three trays are divided amongst the remaining 

 arthropods, which are illustrated in the same manner as the 

 insects. 



The sub-kingdom Moilusca occupies six trays. Here, again, 



