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spores and spore-cases of the common polypody. The spore- 

 case here is provided with a sort of spring, by the action of 

 which the spores are violently ejected, catapult- fashion. The 

 remaining preparations show the structure of the leaf-stalk 

 and root of common types of ferns. 



c. Local Flora. In this collection it is designed to illus- 

 trate every plant-species growing naturally or without culti- 

 vation within one hundred miles of New York City. For 

 the most part specimens of the plants themselves are used, 

 but in cases where the structure of the plants renders this 

 method undesirable, or impossible, a photograph or a draw- 

 ing is substituted for the plant-specimen. This collection 

 is displayed in swinging frames which are placed so as to 

 correspond in a general way to the sequence of the cases of 

 the synoptic collection already described ; thus, the first stand 

 is near the first museum case as one enters the west hall from 

 the top of the staircase. All of the plant groups are here 

 represented by those members that occur locally, and the 

 characteristics of the several groups as mentioned under the 

 Synoptic Collection also apply here. 



3. THE MUSEUM OF FOSSIL BOTANY 



This collection, installed in the basement, is designed to 

 show the successive stages of evolution through which the 

 ancestors of our living flora have passed since the time of the 

 first appearance of plant life on the earth, as far as the 

 remains of extinct plants have been preserved. The arrange- 

 ment adopted is therefore based upon the sequence of the 

 geological time divisions : Eozoic, Palaeozoic, Mesozoic and 

 Neozoic, and their sub-divisions into periods ; Laurentian, 

 Cambrian, Lower Silurian, Upper Silurian, Devonian, Car- 

 boniferous, Triassic, Jurassic, Cretaceous, Tertiary, Quater- 

 nary and Recent or Modern. This arrangement is therefore 

 geological, but incidentally it is also biological, and is based 

 on the same system as that on which the synoptic collection 

 of the museum of systematic botany is arranged, inasmuch 



