3. Die höheren Lehenseinheiten. 453 



920) Thompson, F. 1)., The thyroid and parathyroid glands 



throughout Vertebrates. 



(Proc. Royal Boc. B. S2.557B. p. 389—390. 1910. — Füll Paper: Transactions of Roy. 

 Soc. B. 201. p. 91— 132. 5plates. 1910.) 



A summary of the origin and relations of the thyroid and parathyroid 

 glands in all the classes of Vertebrates. The thyroid and parathyroids are of 

 somcwhat different embryological origin, but become parts of one apparatus in 

 the Mammalia. The evidence for the function of the parathyroids is discussed. 



Doncaster (Cambridge). 



021) Combes, R., Variations subies par les composees hydrocar- 

 bones dans les feuilles, ä l'epoque de la chute de ces organes. 



(Association francaise pour l'avancement des Sciences 38 [Lille 1909]. p. 525 — 531. 

 Paris, Masson et Cic. 1910.) 



A l'epoque de leur chute, les feuilles renferment encore de grandes quan- 

 tites d'hydrates de carbone divers: Sucres, dextrines, composes amylaces; dans 

 certaina cas, il se produit meme une accumulation de ces corps dans les feuilles, 

 ä l'epoque ä laquelle elles se detachent de l'arbre. 



De ce que les feuilles, au moment oü elles tombent, renferment un grand 

 norabre de substances, il ne faut pas conclure que ces dernieres sont des 

 produits d'excretion. 



L'analyse de ces phenomenes est tres complexe et des facteurs tres divers: 

 abaissement de temperature, ralentissement du mouvement de la seve brüte, 

 reglent les phenomenes de migration des substances contenues dans la feuille. 



C. L. Gatin (Paris). 



022) Höft, Wasseraufnahme der Tiere und Milchergiebigkeit. 



(Milch-Ztg. 39,27. p. 314. Juli 1910.) 

 Sammelreferat aus der diesbezüglichen Literatur der letzten Jahre. 



Schröter (Breslau). 



023) Collinge, W. E., Note on the feeding habits of the earwig, 



Forficula auricularia. 



(Journ. Econ. Biology 5,2. p. 08. 1910.) 

 1t has often been doubted whether earwigs damage the flowers in which 

 they hide. Evidence is given that they feed largely on the flowers of the 

 honey suckle (Lonicera periclymenum) and the Dahlia, and destroy large 

 quantities of the flowers. Doncaster (Cambridge). 



024) Butler, A. G., A few words respecting insects and their 

 natural enemies. 



(Trans. Entomological Society of London 1,11. p. 151—154. 1910.) 

 The author summarises his observations on feeding birds with variously 

 „protectively" and „warningly" coloured insects. Birds are afraid of objects 

 to which they are not accustomcd, so that a ground-feeding bird may reject 

 the larva of C. vinula while a tree-feeding bird takes it immediately. The 

 efficacy of warning colours is doubted, for a bird will soon leara what species 

 are unpleasant even if not strikingly coloured. Larvae like those of A. gros- 

 sulariata and P. bucephala which are rejected by some birds are eaten 

 by others. Hairy larvae are usually rejected by small birds but eaten by 

 [arger ones. 



Protective colouration or form is probably of valne in deceiving a passing 

 bird not pressed by hunger, but a bungry bird searching for food is rarely 



