264 



SCIENCE 



[YoL. VI., No. 138. 



formed animals quit the site, and, during the next 

 few days, could be found under logs, and in other 

 suitable places at some considerable distance from 

 it. On the contrary, should a rain in the mean time 

 fill the pond again, and flood over these shallow parts, 

 the transformations were checked; and those with 

 gills and branchiae in all stages of change, once more 

 took to the water. When huddled together in the 

 shallow places, the large and strong ones devoured 

 the smaller and feebler forms ; and the different ap- 

 pearance of the two was very striking upon the most 

 superficial examination. 



One day in July the whole north half of this pond 

 suddenly ran dry; and I must confess the sight its 

 bottom presented during the following day was one 

 of the most extraordinary, and at the same time 

 most interesting, that I ever beheld, and, after what 

 has been said, can be better imagined than described. 

 It absolutely swarmed with these creatures, whose 

 organizations were accommodating themselves to the 

 new condition of affairs as rapidly as the laws gov- 

 erning the changes permitted. The study would 

 have furnished food for a small volume. 



Axolotls are also affected by the character of the 

 ponds or swamps they live in, the same species show- 

 ing all manner of shades in their coloration. Those 

 in shallow ponds with little or no vegetation, and 

 hard clay bottoms, grow to be very light colored, and 

 long retain their larval forms. 



No doubt many such ponds as I have described 

 exist all over this south-western country; and a mo- 

 ment's reflection will make it clear to us how the 

 metamorphosis of this creature tends to save thou- 

 sands of their lives, when the region is visited by a 

 protracted drought, and their places of water resort 

 fail them. The preservation of the form is thereby, 

 to a great extent, protected. 



Dr. R. W. Shufeldt. 



Fort Wingate, N. Mex., 

 Aug. 12. 



THE SONG-NOTES OF THE PERIOD- 

 ICAL CICADA. 



There are few more interesting subjects of 

 study than the notes of insects and the differ- 

 ent mechanisms b}^ which they are produced. 

 They interest ever}' observant entomologist ; 

 and it is difficult to record them in musical 

 symbols that can be reproduced on musical in- 

 struments, some of the more successful and 

 interesting attempts in this direction having 

 been made by Mr. S. H. Scudder. I have 

 studied closely the notes of a number of species, 

 and have published some of the observations.^ 



In the notes of the true stridulators more 

 particularl}', as the common tree-crickets and 

 kat3'dids, I have been impressed with the vari- 

 ation both in the pitch and in the character 

 of the note, dependent on the age of the 

 specimen, and the condition of the atmosphere, 

 whether as to moisture, density, or temperature. 

 Yet, with similarit}' in these conditions, the 

 note of the same species will be constant and 

 easil}' recognizable. 



A few remarks upon Cicada septendecim will 

 doubtless prove of interest now that the species 

 has been occupying so much attention. I do 

 not find that the notes have been anywhere 

 very carefully described in detail, nor would 

 I pretend to put them to musical scale. Writ- 

 ing seventeen years ago, I described the notes 

 in a general way, as follows : — 



" The general noise, on approaching the in- 

 fested woods, is a compromise between that of 

 a distant threshing-machine and a distant frog- 

 pond. That which they make when disturbed 

 mimics a nest of 3^oung snakes or 3'oung 

 birds under similar circumstances, — a sort of 

 scream. They can also produce a chirp some- 

 what like that of a cricket, and a very loud, 

 shrill screech, prolonged for fifteen or twenty 

 seconds, and graduallj" increasing in force, and 

 then decreasing." ^ 



There are three prevalent notes, which, in 

 their blending, go to make the general noise as 

 described above. These are, — 



First, That ordinarily known as the phor- 

 T-r-r-aoh note. This is the note most often 

 heard during the early maturity of the male, 

 and especiall}' from isolated males or from 

 limited numbers. It is variable in pitch and 

 volume, according to the conditions just men- 

 tioned as generallj' affecting insect melodists. 

 Its duration averages from two to three sec- 

 onds ; and the aoh termination is a rather 

 mournful lowering of the general pitch, and is 

 also somewhat variable in pitch, distinctness, 

 and duration. In a very clear atmosphere, 

 and at certain distances, an individual note 

 has often recalled that made at a distance by 

 the whistling of a rapid train passing under 

 a short tunnel. But when heard in sufficient 

 proximit}', the rolling nature of the note will 

 undoubtedl}' remind most persons more of the 

 croaking of certain frogs than of an}' thing else. 

 I have heard it so soft and low, and so void of 

 the aoh termination , that it was the counterpart 

 of that made by Oecanthus latipennis Rile}^ late 

 in autumn, and when shortened from age and 

 debility of the stridulator. 



Second, The loudest note, and the one 

 which is undoubtedly most identified with the 

 species in the popular mind, is what may be 

 called the ' screech. ' This is the note described 

 b}" Fitch as " represented by the letters ^s/i-e-e- 

 E-E-E-E-E-e-ou^ uttered continuousl}", and 

 prolonged to a quarter or half a minute in 

 length, the middle of the note being deafen- 

 ingly shrill, loud and piercing to the ear, and 

 its termination graduall}- lowered till the sound 



1 3d rep. ins. Mo., U, 153, 154; 4th do., 139; 6th do., 150- 



Ist rep. ins. Mo., 24. 



