562 SCIENCE PROGRESS 



Osmundaceous and Botryopteridean forms. In his paper on 

 " Monocarpy and Pseudo-monocarpy in the Cycadeoids " 

 {Amer. Journ. Bot., vol. Ixxxi, pp. 218-30, pis. ix-xii), G. R. 

 Wieland discussed Monocarpy in a few recent examples, and 

 developed the interest of the character in relation to the 

 Cycadeoidea, with their immensely numerous and complex 

 fructifications. 



From Tertiary beds C. Reid and J. Groves described a large 

 number of beautifully preserved Chara fruits, and suggested 

 that the group might supply the zonal types which are so much 

 wanted for fresh-water strata (see " The Charophyta of the 

 Lower Headon Beds of Hordle Cliff," Quart. Journ. Geol. Soc, 

 vol. Ixxvii, pt. 3, pp. 175-92, pis. iv-vi. Probably of Tertiary 

 age were the numbers of specimens brought back from 

 Christmas Harbour in 1840 and now in the British Museum ; 

 detailed examination of their structure, however, has only 

 revealed two species (see W. N. Edwards on " Fossil Coniferous 

 Wood from Kerguelen Island," Annals Bot., vol. xxxv. No. 109, 

 pp. 609-617, pi. xxiii) ; namely, Cupressinoxylon Antardicum 

 Beust and Dadoxylon kerguelense Seward. 



In general one must report that the year 1921 marks a low 

 ebb of the tide of palaeobotanical production. 



ENTOMOLOGY. By A. D. Imms, M.A., D.Sc, Institute of Plant Pathology, 

 Rothamsted Experimental Station, Harpenden. 



Since the last report on Entomology (Science Progress, 

 October 1921) the following are among the more important 

 contributions that have come to notice. 



General Entomology. — R. A. Muttkowski {Ann. Ent. Soc. 

 Am., 14, 150-56) has published the first paper of a series of 

 studies on respiration in insects. As at present understood, 

 atmospheric oxygen is led directly to the tissues by the tracheae, 

 while the blood acts as the carrier of food and metabolic pro- 

 ducts. Some workers, however, have maintained that the 

 blood is not concerned with the transportation of oxygen at 

 all. This latter statement has proved difficult to reconcile 

 with facts, more especially in insects that are devoid of tracheae. 

 Muttkowski finds that both O and COg are present in insect 

 blood, the major portion of these gases being held by a re- 

 spiratory protein, and the species examined show the presence 

 of copper, which is interpreted as forming the basis of a 

 respiratory pigment-haemocyanin. The only exception is found 

 in certain Chironomid larvae where the respiratory pigment has 

 long been known to be haemoglobin. In addition to its recog- 

 nised function of circulating food and metabolic products, the 

 blood, therefore, aids the tracheal system in the distribution 

 of O and the removal of CO2. 



