VOL. XXIir. No. 2.] 



POPULAR SCIENCE NEWS. 



27 



Conn., by Master Leighton Foster, the first part of 

 June, and from appearances had been hatched but 

 two or three days. 



The single body, with the usual four legs and a 

 tail, carries two equal, and in every respect, normal 

 and well-developed heads and necks, which are 

 throughout entirely free and distinct. The two 

 heads see, hear, eat, drink, sleep, breathe, and move 

 independently. The carapace, to external appear- 

 ance, is well formed and natural, save that it is 

 broader than long by nearly one-fourth, and its ver- 

 tebral line is a little curved to the right, with the 

 back slightly humped. But none of these are no- 

 ticeable deformities, had it a single head. Its ap- 

 pendages are perfectly natural as far as their form 

 is concerned. 



This little monster still lives (Sept. 4), and has 

 increased in size at least one-third during the past 

 fourteen weeks. It is active and apparently healthy, 

 and bids fair to survive this season at least. It eats 

 voraciously when fed by familiar hands; but a fly 

 or cricket is often a bone of bitter contention. The 

 first to seize its food becomes at once involved in a 

 stubborn tug of war with its other self, which ends 

 only when the morsel separates. The two heads 

 cat with equal readiness, yet often the appetite of 

 the one is greater than that of the other. Some- 

 times one head turns slowly around and snaps at 

 the vellow eye of the other, obviously mistaking it 

 for something to eat. Of course the head and neck 

 of the one assailed is straightway withdrawn into 

 the common protecting shell, where they can find 

 shelter one at a time or together; but in the latter 

 case it is plainly crowded, and the encroachment on 

 tortoise prerogatives means a renewal of hostility, 

 and a beating of their heads together till a com- 

 promise is effected. These little misunderstandings 

 are always settled in a spirited way, and are exceed- 

 ingly ludicrous. Although rather frequent, they 

 never arise save when the two heads are disposed to 

 w ithdraw to their shell simultaneously ; at other 

 times each in his turn enjoys the privilege. One 

 often withdraws and sleeps while the other is per- 

 fectlv wide awake. And then the one awake, look- 

 ing about to the right and left, sometimes starts off 

 vigorously, but only to find itself describing a circle, 

 round and round as if on a pivot, for such in fact 

 the sleeping side actually becomes. And generally 

 it continues to use its two feet as best it can, scurry- 

 ing around in an endless circle, until the sleeper, 

 aroused by the commotion, puts out its head, looks 

 about, and then shuttles off with its companion. 

 There is no concerted action in the use of the feet, 

 as in the normal tortoise, which first puts one fore- 

 foot forward and follows this with the diagonally 

 opposite hind-foot, and so on. But, as should be 

 expected, the two-headed tortoise, with its two am- 

 bulatory systems, puts out both fore-feet at once, 

 leaving its fore-parts without support, so that they 

 drop and rest on the plastron ; then the hind-feet 

 advance, and the hinder extremities, left in their 

 turn without support, drop, and thus it advances by 

 an awkward rocking gait. 



But these twin heads have finally learned to adapt 

 themselves in various ways to their circumstances. 

 This is especially striking in the matter of walking. 

 By repeated failures, each has discovered that when 

 its companion sleeps, or is not disposed to move, 

 any activity on the part of either is circumscribed 

 by the narrow circle whose radius is the breadth of 

 theircommon body- Accordingly, now, when either 

 has made a few bootless revolutions, it stops short 

 and extending its two feet laterally, seizes with its 

 claws anything offering resistance, and so slowly 

 and laboriously drags itself sidewise, crab-like. By 

 this device, to which they resort so repeatedly that 

 itcannot be counted mere chance, they can travel on 



indefinitely. When placed on smooth ground, free 

 from grass and obstructions, their first manoeuvre, 

 after turning the right head to the right, the left to 

 the left, is to start off resolutely in these two direc- 

 tions at once, the rather remarkable resultant of the 

 two forces in opposite directions being a straight 

 line directly backward ; they make progress for a 

 foot or two in the wrong direction, then agree on a 

 course and start off together. In the grass or weeds 

 they are quite helpless, because when a stalk of 

 grass is encountered, one head chooses the right 

 course, the other the left, that is, they straddle it, 

 and being equals in strength, neither side succumbs, 

 so they stand there tugging away until tired out. 



It is interesting, though not surprising, that two 

 heads so nearly one should have different tempera- 

 ments- The' right head, on most occasions, is the 

 more timid and irascible, retracting or dodging at a 

 passing fly, or the approach of a strange animal. 

 The left head, on the other hand, seems bold and 

 energetic. It is difiicult to conceive of any two in- 

 dividuals, growing up under surrounding circum- 

 stances, more completely identical than these. Yet, 

 like the South Carolina negresses. called the Two- 

 headed Nightingale, the dift'erence in their disposi- 

 tions furnishes new evidence that, though the origin 

 and environments be precisely the same, the results 

 are not necessarily so. 



To what extent the digestion, respiration, circula- 

 tion, and nervous .systems are united or separate is 

 at present only open to conjecture. The alimentary 

 canals, in all probability, become united in one 

 stomach, after leaving the two necks, and remain so 

 to the anus, which is single. I have noticed that 

 while the two heads eat equal amounts, yet at one 

 feeding the left head perhaps shows the greater ap- 

 petite, at another time the other- But no risks can 

 be taken by experimenting with such a pet, or we 

 could feed one at the expense of the other for a 

 short time. By watching the expansions and con- 

 tractions of the throat, where the hyoid plays so 

 important a part in chelonian respiration, we find 

 that each of the heads breathes regularly, but inde- 

 pendently, as much so as if they belonged to dis- 

 connected individuals. At regular intervals they 

 can be seen opening their mouths and gaping, as if 

 the supply of oxygen was insufticient, as it doubt- 

 less is. This is their only visible sign of weakness. 



As already stated respecting the nervous system, 

 it is perfectly patent that the appendages of the 

 right and left sides belong to. and respond only to, 

 their respective heads- So noticeable is this inde- 

 pendence in the action of the four feet, which other- 

 wise seem to belong naturally enough to the one 

 carapace, that many who see its attempts at walk- 

 ing are led to "wonder if the other legs of the 

 double shell are not growing inside." 



There seems to be absolutely no co-operation be- 

 tween the left side and the right, and yet they re- 

 peatedly start at the same time to do precisely the 

 same thing, eat, swim, or walk. When by any 

 mischance it falls over on its back, the two heads 

 work in opposite directions to right the shell, and 

 so without help it could never, like an ordinary tor- 

 toise, extricate itself from the predicament. 



The length and flexibility of each neck shows it 

 has the full number of cervical vertebne, confluent 

 at the first thoracic vertebra. In other respects its 

 skeleton is quite normal. The dermal plates show- 

 a few unimportant variations. There is tne usual 

 nuchal plate in front on the middle line, and two 

 pygal plates behind. Between those two points on 

 either side are twelve marginal plates; the usual 

 though not invariable number being eleven. On 

 the right side an extra scute is wedged in among 

 the costal plates, making five on that side to four 

 on the other. The five vertebral or neural plates 



preserve their relative positions, but have some- 

 what distorted forms. The first of these is divided 

 by a suture through its length. The fifth is com- 

 posed of four small irregular plates, and pre.sents a 

 fissure where it did not unite on the middle line. 

 The plates of the plastron show but one irregular- 

 ity, a doubling of the gular plate. A suture is seen 

 in the right femoral plate ; and the right infra-mar- 

 ginal plates are united, the left separate; but these 

 are not peculiarities, however. 



When the time arrives for the promised dissection 

 of this curious little monstrosity, I shall hope to 

 find anatomical peculiarities of some consequence. 

 — E. II. Barbour, in Am. Journal of Science. 



[Specially Reported for The Popular Scienc; A'eiOT.] 



METEOROLOGY FOR DECEMBER, 188S, 



WITH REVIEW OF THE YEAR. 



TEMPEKATUKE. 



The weather has been unusually warm and pleas- 

 ant for December. The lowest point reached bv the 

 mercury was 5" on the morning of the 14th, and the 

 highest, 60° on the evening of the 17th. The cold- 

 est day, the 14th, averaged 11°; the warmest, the 

 t7th, 56 1-3°. The first week in the month was 

 much cooler than the last, the former averaging 

 33.62°, the latter, 41.24° The entire month was 

 4.86° warmer than the average for December in iS 

 years, and has been exceeded in this respect but 

 twice, 1877 and iSSi, during this period. The 

 change from the 17th to the iSth was very sudden, 

 the mercury falling 35° in twenty-four hours. 



SKY. 



The face of the sky in 93 observations gave 49 

 fair, 12 cloudy, 22 overcast, 9 rainy, and i snowy; 

 a percentage of 52.7 fair. The average fair the 

 last iS Decembers has been 49.8, with extremes of 

 40.9 in 18S7, and 75.3 m 1877. ^" December with- 

 in the last ten years has had so little cloud as the 

 present. The last third of the month was mostly 

 fine weather, with .several bright and beautiful 

 sunsets. The morning of the loth was foggy. 



PRECIPITATION. 



The rainfall the last month, including a small 

 amount of snow on the 9th, which disappeared at 

 once, with rain, was 6.54 inches, while the average 

 for the last 20 Decembers has been only 4.00, with 

 extremes of .73 in 1S75, and 7,89 in 1884. i'le pre- 

 cipitation the last year, including 40 inches of snow, 

 melted, has been quite remarkable, amounting to 

 64.40 inches, while the average in 20 years has been 

 only 46.61, with extremes of 32.26 inches in 18S3. 

 and 64.40 in 18S8; one extreme being almost exactly 

 double the other. The amount of the first three 

 and the last five months was 54.52 inches, while the 

 other four months furnished only 9. 88 inches. 



PRES.SURE. 



The average pressure the last month was 29.925 

 inches, with extremes of 28.90 on the i8th, and 30.45 

 on the 30th, a range of 1.55 inch. The average 

 pressure the last 15 Decembers has been 29.951, 

 with extremes of 29.804 in 1876, and 30.073 in 1879, 

 a range of .269 inch. It is .seldom that the barom- 

 eter falls below 29 inches. In the last sixteen years 

 it has occurred at the hours of ob.servation but six 

 times. The lowest of these depressions was 28-70 



