52 



THE GUIDE TO NATURE 



Ants' Heads Do Walk About. 



In our May number we quoted from 

 "The American Botanist" an article en- 

 titled, "Interesting- But Not True." We 

 suggest that in criticising others, one 

 should say nothing that may be criticised 

 by those others. The following letters 

 are self-explanatory : 



Washington, D. C. 

 To the Editor: 



I am enclosing a page from your May 

 number of The Guide to Nature with 

 a slight correction. It so happens that, 

 so far as I know, I was the first to re- 

 port the facts about an "ant's^head walk- 

 ing by itself without a body." , 



I take the following from my note- 

 book of July loth, 1887, the facts after- 

 wards being reported to the Entomo- 

 logical Society here: "Hollis, N. H., 

 July 10. 



"While sitting on the front steps I no- 

 ticed the headless bodies of some black 

 ants (Camponotus pennsylvaniciis) 

 which were still alive. On looking 

 around carefully I found several heads 

 lying detached. On examination each 

 head was found to be occupied by a 

 small, live, white worm. They were able 

 to move around by keeping the head on 

 its flat (posterior) surface and by 

 elongating themselves, pushing their 

 house backward — " 



Several years later Mr. E. A. 

 Schwartz of the Agricultural Depart- 

 ment reported a full study of the sub- 

 ject and identified the adult of the worm 

 as a parasitic fly ( ?) which deposited its 

 eggs on the back of the ant's head. 



"The American Botanist," from which 



you quote should change its quotation 



to, Be sure you are right, then go ahead. 



Sincerely yours, 



William H. Fox, ^I. D. 



^ * * 



\Vashington, D. C. 

 To the Editor : 



I have yours of the 4th, with letter 

 from Dr. William H. Fox of this city 

 and clipping from the May number of 

 The Guide to Nature. Doctor Fox is 

 correct, with the single exception that 

 the man who wrote the second article 

 conveying the determination of the para- 

 site and so on was not Mr. E. A. 

 Schwarz. but Mr. Theodore Pergande of 

 this Bureau. You will find an account 

 of this curious phenomenon of an ant's 

 head apparently walking by itself in my 



"Insect Book" published by Doubleday 

 Page &Co., on pages 147-148, under the 

 head of "The Hump-backed Flies (Fam- 

 ily Phoridae)." I quote: 



"Life History of the Ant-Decapitating 

 Fly 

 {Apoccphalus pcrgandei Coquillett.) 

 "It would be rather a misnomer to call 

 this a typical life history since this form 

 seems peculiar in its habits and rather 

 aberrant among the Phoridae, but the 

 observations which have been made upon 

 it by Dr. W. H. Fox and Mr. Theo. Per- 

 gande have been more complete than any 

 which have been made upon other mem- 

 bers of the family, so it is here included. 

 A common black ant (Camponotus perui- 

 sylvanicus) is the host of this little 

 hump-backed fly. In the District of Co- 

 lumbia and in New Hampshire the fly 

 may be found in midsummer darting 

 about the moving ants on tree trunks 

 and elsewhere and finally succeeding in 

 laying its ^gg, sometimes after a strug- 

 gle, on the neck of the ant. The Qgg 

 hatches and the young larva bores direct- 

 ly into the head of the ant. As it en- 

 larges it eats out the whole head cavity, 

 the head breaks ofif from the body of the 

 ant and moves about independently, pro- 

 pelled by the body of the contained mag- 

 got which extrudes partly from the neck 

 hole. The larva of the fly transforms to 

 pupa with the last larval skin in the cut 

 oft' ant's head and the adult fly issues in 

 the course of from two to three weeks. 

 To see an ant's head walking off by itself 

 is a curious sight, yet it is common 

 enough where this fly abounds. Dr. Fox 

 named it, appropriately enough, 'the ant- 

 decapitating fly.' " 



Sincerely yours, 



L. O. Howard, 

 Chief of Bureau. 



The latest of the long series of mono- 

 graphs on "The Natural History of 

 New England" brought out by the 

 Boston Society of Natural History is 

 by W. C. Kendall, associate of the 

 United States Bureau of Fisheries. It 

 comprises part T of a proposed mono- 

 graph on the salmon family, and is 

 given over exclusively to the trouts. 

 In addition to the usual minute de- 

 scriptions in the hundred quarto pages, 

 there is much historical information, 

 together with seven large and beauti- 

 ullv colored plates. 



