— 173 — 



farther north. It is rich in composition ; nearly a quarter of all the 

 arborescent s[;ccies of tlie Atlantic forest are found within this insignificant 

 region." 



In these few wurds the extent of the semitropical insect fauna is also 

 sketched, but Prof Sargent omits to emphasize the island-like distribution 

 of the semitropical forest which as a matter of course exists on the Keys 

 but is maintained throughout on the mainland. 



This distribution of the semitropical fauna which suirounds, like a 

 necklace of pearls by far the largest portion of the j)eiiincula nf Florida 

 IS certainh- a mo>t remarkable one, and has, I think, no parallel in any 

 other Country of the glol)e. 



In a paper read at the March (1888) meeting of the Kntomological 

 Society of \Vr.shing;on, Mr. Uhler, while speaking on the Hemipiera col- 

 lected by my.-«ell in south-eastern Florida, stated tliat the present Hemip- 

 terous fauna of North AiiiCiica is largely derived from the neo-tropical 

 fiiuna, and that the comparatively few leally nearctic forms in Southern 

 Floiida have a hard struggle with the invaders from the South. His first 

 assertion is undoubtedl)- correct and holds triie aL^o of the other Orders 

 of insects; but Mr. Uhler omits 10 stale that the immigration to which 

 heVefers and which shaped the character of the present fauna of tlie North 

 American continent, took place at a very remote age, viz : at the end of 

 the Ice period, long before there existetl a Southern Florida. The settle- 

 ment of West Indian plants and insects which has been tlie subject of 

 my communication is, geologically speaking, of quite recent date and, 

 in fact, is still going on. This West Indian colony occupies, as we have 

 seen, a very modest place in Florida and certainly does not infringe upon 

 or contend with the continental forms. Some species have acquired, and 

 some others no doubt will acquire the power to change their food-habits 

 and extend their geographical range northward, but the majority will re- 

 main confined to the isolated spots covered by the semitropical forest 

 and will never compete with the North American forms. Yes, this semi- 

 tropical flora and fauna stands even in imminent danger of being con- 

 siderably restricted by the agency of Man since the hammock land, on 

 account of its rich soil, is rapidly brought under cultivation. Thus the 

 once famous semitropical hammock of Lake Worth will have entirely dis- 

 appeared ere long. 



During my stay on the shores of Biscayne Bay I witnessed myself 

 the destruction by cultivation of some of the prettiest pieces of semitrop- 

 ical hammock land, and if on the island of Key West the building boom, 

 which flourished at the time of my visit, holds on for only three or four 

 years, not the slightest trace will then be left of the hammock, and the 

 semitropical insect fauna of that island will be a thing of the past. Still, 



