66 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



The distribution of the plant forms is exceedingly interesting. 

 It seems to be determined by the accidents of visitation. These 

 may be classified somewhat as following: (a) Visitors carrying 

 spores on clothing or on staffs and other impedimenta, (b) By 

 the very few cave insects that travel widely, such as Anophthalmus. 

 {c) By the bats, which enter by the hundreds of thousands in 

 the late fall for hibernation purposes, {d) By the migrations of 

 the blind rat, Neotoma. 



The first of these causes relates only to the distribution along 

 such avenues as are exhibited to visitors and is, therefore, of very 

 definite application. The others are all of indefinite operation, 

 may be continuous or discontinuous and are by no means constant. 

 It is well to keep these facts in mind as aiding to explain certain 

 fitful seasons of abundance or scarcity. All but two of the plants, 

 Mucor Mucedo and Laboiilbenia siibterranea have been found only 

 along the paths frequented by sight-seers. This Mucor occurs 

 wherever there is sufficient moisture and food supply. The second 

 form has been found thus far only on dead Anophthalmi, the blind 

 cave beetle. This is a most instructive fact and seems to justify 

 the conclusion that prior to the advent of man the cave was 

 practically devoid of plant life. 



There are no representatives of the rusts, smuts, and mildews 

 among the forms discovered. These forms are entirely parasitic 

 on the higher forms of plants, the chlorophyll-bearing species. 

 No plant containing a single chloroplast has been discovered over 

 a study period of some five years. Diatoms alone have been 

 discovered in the plankton of Echo River and the Dead Sea. Nor 

 did the microscope reveal a single pyrenoid in the only diatom 

 represented — a transparent Navicida for which I have not found 

 a specific name. Many specimens were examined. 



The underground rivers and smaller streams are fed by "sinks" 

 or depressions of sometimes very great extent. They are caused 

 by the solution of the underlying St. Louis oolitic limestone and 

 the falling in of the superposed Chester sandstone — which together 

 constitute the simple geology of the region. These sinks are 

 mentioned thus particularly because, (a) In the waters that pass 

 through them to the cave many fungus spores must enter, and 

 (6) It would seem to explain the presence of Navicula in the 

 plankton. 



At the several lunching stations food in abundance occurs on 



