April <^, 1877] 



NATURE 



491 



The motion was put to the meeting and carried unani- 

 mously with loud applause. 



Major Testing said that, as representing the depart- 

 ment, he was sorry he could give no more information 

 than the lecturer had. The Government had not yet 

 announced its intention as to what it would do in the 

 matter. It had lately had many other matters on hand. 

 With regard to the lectures, it was felt that it was hardly 

 fair to continue to ask men of science to give their 

 services gratuitously, and until some arrangement for 

 fees could be made, he thought the lectures would pro- 

 bably remain in abeyance. It would give him pleasure to 

 forward the resolution so unanimously carried to the head 

 of his department as requested. 



THE DEVELOPMENT OF BATRACHIANS 

 WITHOUT METAMORPHOSIS 



METAMORPHOSIS, or the transition of the animal 

 through an intermediate stage between the ovum 

 and the adult, has hitherto been considered by modern 

 naturalists a special characteristic of the Batrachians 

 amongst the Vertebrates, and as one of the main 

 features which distinguish them from the true Rep- 

 tiles, with which they were formerly united. It is, there- 

 fore, surprising to learn, as we do from a recent com- 

 munication of Dr. Peters to the Royal Academy of 

 Sciences of Berlin, that there are cases in which no such 

 metamorphosis takes place, and the young frog is deve- 

 loped directly from the egg without showing any signs of 

 what is usually called the " tadpole " stage. 



Dr. Pcters's noteworthy discovery is based upon obser- 

 vatioiis made by Dr. Bello, Herr Krug, and Dr. J. Gund- 

 lach, in Porto Rico, on the development of a West Indian 

 tree-frog — Hy lodes niartiniceiisis, which seems to be not 

 uncommon in Porto Rico, and is there generally known by 

 the vernacular term Coqui. 



Five years ago Dr. Bello stated ^ that a tree-frog in 

 Porto Rico called Coqui was remarkable from the fact that 

 the young came out of the eggs in a perfect condition, and fit 

 for life in the air. " In 1870," he says, " I observed in a gar- 

 den an example of this species upon a liliaceous plant, on 

 which about thirty eggs were clustered together in a 

 cotton-wool-like mass ; the mother kept close to them as if 

 she mtended to incubate. A few days afterwards I found 

 the little frogs from two to three lines long just born, with 

 all their four feet perfectly developed, springing about, and 

 enjoying life in the air. In a few days they attained their 

 full size. This garden is surrounded by walls six feet 

 high, and there is no water in it. The so-called lily 

 [(which appears to be an introduced species of Crinuin) 

 jalways contains a little water in the receptacles, but is not 

 a water-plant." 



The translator of these observations rightly remarks 

 that the exclusion of the animal out of the egg was not 

 actually witne:.sed in this case, and that it was possible 

 even in the short time which elapsed between when the 

 eggs were seen and the young frogs appeared, some 

 metamorphosis might have taken place, especially as the 

 subsequent development seems to have been uncommonly 

 quick. 



These short observations of Dr. Bello appear to have 

 attracted the less attention inasmuch as the development 

 of tree-frogs from eggs placed in dry situations in frothy 

 masses had been already observed and described in 

 :ropical countries. In 1867 Herr Hensel published some 

 interesting observations on Cystigiiathtis mystacinus, in 

 ;he forests of Rio Grande do Sul,^ and last year Dr. 

 Peters laid before the Academy of Berlin the extraordi- 

 lary discoveries of Buchholz concerning the egg-masses 

 )f Chiroina7itis guineensis laid upon trees in Guinea. Be- 



' " Zoologische Notizen aus Portorico," in " Der zool. Garten," 1871, 



1.351- 

 = Sitz. d. Ges. Nat. Freunde zu Berlin 1867, p. 10, and Arch. . Nat. xxiii. 

 t. I, p. 129. 



sides this the development of Alytes obstetricans between 

 the hind-legs of the male in the ordinary way, and, through 

 Herr Weinland's brilliant investigations, the metamor- 

 phosis of the young in the dorsal sacs of the females 

 of Opisthodeiphys and Nototrema, were facts so generally 

 known that it seemed highly improbable that any Batra- 

 chian should be developed without metamorphosis. 



Under these circumstances it is of the greatest interest 

 to be able to state that Dr. Bello's information has been 

 fully corroborated by recent observations of Dr. Gund- 

 lach and by preparations which he has transmitted to 

 Berlin. 



"On May 24, 1876," Dr. Gundlach says, "I heard a 

 singular call like that of a young bird, and went to see 

 what it was. Between two large orange-blossoms I per- 

 ceived a leaf-frog, and on taking hold of it, found I had 

 captured three males and a female of the Coqui. On 

 putting them into a damp glass, one of the males 

 quickly placed himself on the female and grasped around 

 her. Not long afterwards she had laid from fifteen to 

 twenty eggs, which, however, mostly soon disappeared — 

 perhaps eaten. 



" There were subsequently laid five eggs, round, with a 

 transparent covering, which I removed and placed on some 

 wet slime. The inner yelk, of a whitish or pale straw- 

 colour, contracts a little, and then the tail is seen forming. 



Fig. I. — Egg of Hylodes martzntcensis, twelve days old, lower surface 

 Fig. 7. — Young oi Hylodes as it leaves the egg ; c, tail. Fig. 3. — Adult 

 male Hylodes, natural size. 



In eight days this was quite clearly visible, as well as 

 the eyes, and the red pulsating blood-vessels. Later 

 on traces of the legs became manifest. I was now absent 

 for some days, and when I returned, on June 6, found the 

 eggs still, but on the next morning, the young were out, 

 and had no trace left of the tail. 



" Afterwards I found between two leaves of a large 

 Amaryllid, just like Dr. Bello, a batch of more than 

 twenty eggs, upon which the mother was sitting. I cut 

 off the leaf, along with the eggs — upon which the mother 

 jumped off — and placed them in a glass with some 

 damp earth at the bottom. About the fourteenth day, 

 having returned from an excursion, I found, at 9 A.M., all 

 the eggs hatched, and I remarked on the young ones a 

 little white tail (see Fig. 2, c), which by the afternoon had 

 altogether disappeared." 



Dr. Gundlach's collection, as Dr. Peters tells us, 

 contains four eggs of this frog, with embryos. They 

 consist of a transparent vesicle of from 4 5 to 5'5 mill, 

 in diameter, which is partly occupied by an opaque 

 flaky white mass. The vesicle is filled with a trans- 

 parent fluid, which allows one to see every part of 

 the swimming embryo quite clearly. The embryo, as 

 in the case of mammals, is curved together on the 

 lower surface, so that the head approaches the lower ex- 

 tremities, which, as well as the anterior extremities, are 

 drawn together under the belly and lie close to the body. 



