1888.] NATURAL SCIENCES OF PHILADELPHIA. 44£ 
The growth of the collection, since it came into the Academy’s 
possession is as follows:— 
Specimens purchased in 1884, ..... 60 
Specimens purchased in 1885,. 104 
Specimens purchased in 1886,. 114 
Specimens purchased in 1887, ..... 156 
Specimens purchased in 1888, ..... 102 
Total,.536 
The aggregate cost of the 536 specimens has been . $2506.80 
Most worthy of mention among the additions of the year are a 
fine specimen of Calcite in Malachite, a superb Vanadinite and 
Wulfenite from Arizona; these specimens, in color and crystalo- 
graphic form, are the finest ever brought to the city. Other inter¬ 
esting specimens are a single crystal of Gadolenite 6 inches in width, 
by 9 inches in length, said to be the largest crystal ever found ; 
fine large crystals, of Troostite, Tryolite, Erenite, Opal, Turquoise,. 
Thenardite, Trona, Hyalite, Colemanite and others. 
A number of species not heretofore represented in the collection 
have been added.- 
The visitors to the collection have not been as numerous as in 
former years; it may be remarked, however, that those who do visit 
it are persons especially interested in mineralogy or archaeology 
who have made use of it more for the purpose of study than for the- 
gratification of mere curiosity. 
Respectfully submitted, 
Jacob Binder, 
Curator. 
REPORT OF THE BIOLOGICAL AND MICRO¬ 
SCOPICAL SECTION. 
During the year thirteen stated meetings were held with art 
average attendance of ten members. 
Four public lectures were given. 
The following gentlemen were elected members and contributors. 
Members. John T. Pennypacker, 
“ Lancaster Thomas. 
