174 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
the potency of living. He recalls some of his experiments with frozen 
frogs, in which the circulation and other vital movements cease, but 
which revive when thawed, provided the internal temperature has not gone 
below a minimum of — 2 * 5° C. The same is true of the excised heart. 
Prof. Preyer also relates some of his observations on the revival of 
desiccated rotifers and Tardigrades, and maintains that there is no vita 
minima in such cases, but a genuine lifelessness, from which the 
organism may recover. 
Chlorophyll in the Animal Kingdom.* — M. E. Penard discusses 
some of the reputed cases of the presence of chlorophyll in animals, and 
comes to the conclusion that, in the actual state of our knowledge, we 
cannot consider chlorophyll as ever being a direct product of animal 
protoplasm. He does not deny that, in some of the Flagellata, chlorophyll 
exists in chromatophores of endogenous origin, but such forms present 
other characters which are vegetable and not animal in character. 
Origin of the Liver.f — Dr. T. W. Shore has been led by his investi- 
gations to the now recognized view that the “ liver ” of invertebrates is 
not morphologically the same as that of vertebrates. It is the gland of 
the mid-gut, and when present, has essentially the same nature in all ; 
it is composed of caecal pouches, which are lined by secreting epithelium 
and surrounded by connective-tissue membranes. The liver of verte- 
brates is made up of a network of tubules, interlacing with a network of 
blood-capillaries and with no basement membrane separating the blood- 
capillaries from the liver-cells. 
The “ liver ” of invertebrates is essentially a gland, secreting a 
digestive fluid containing ferments ; that of vertebrates is primarily an 
organ of nutrition for the embryo, and has been adapted to perform 
similar functions in the adult ; in its evolution it is intimately associated 
with the absorption of the food-yolk of the egg. The pancreas of 
vertebrates is somewhat similar in structure and functions to the “ mid- 
gut gland ” of invertebrates, but we cannot certainly say whether or not 
the two organs are morphologically equivalent. 
Fauna of Amber.! — Herr R. Klebs has had the opportunity of 
examining several hundred thousand pieces of amber. In it, as is well 
known, various animals, largely insects, became entangled as the amber 
solidified. The order most numerously represented is that of the Diptera, 
and of some of the genera of these there are numerous species — 
CTiironomus being represented by at least forty, and Ceratopogon by 
twenty-six. All the groups of Hymenoptera except the Braconidee 
and Craniidae are represented, and forty-nine of the seventy-five families 
of Coleoptera. Of the Orthoptera the Blattidae are the most numerous. 
Campodea has not been certainly detected. Termites are numerous, and 
there are about one thousand specimens of Microlepidoptera. 
The larger number of Arachnids imbedded were various forms of 
Spiders, but there are also many Mites. Only one true Scorpion has 
been found. As may be supposed, the bulk of the Crustacea are Isopods. 
* Arch. Sci. Phys. et Nat, xxiv. (1890) pp. 638-48. 
t Journ. of Anat. and Physiol., xxv. (1891) pp. 166-97 (1 pi.). 
X Biol. Centralbl., x. (1890) pp. 444-8. See Ann. and Mag. Nat. Hist., vi. (1890) 
pp. 486-91. 
