458 SCIENCE PROGRESS 



Cycadophyta are almost certainly derived from a fern ancestry 

 it follows that all are ultimately traceable to the same source. 

 The conifers closely resemble Cordaitales and are probably 

 derived from them, but the Araucarinese resemble Cordaitales 

 far more closely than do any other conifers and have evidently 

 sprung direct from that group. The transitional conifers of 

 the Mesozoic are either araucarians or cordaiteans well on 

 their way towards Pinaceae, while the Abietineae are very old, 

 and are derived either directly from the Cordaitales or from the 

 most ancient members of the Araucarinese. 



ZOOLOGY. By C. H. O'Donoghue, D.Sc, F.Z.S., University College, 

 London. 



It seems fitting to record here the great loss British zoology 

 has sustained by the death of three of its best known workers 

 and to add our tribute to their memory. Prof. E. A. Min- 

 chin, F.R.S., was justly regarded as one of the foremost Proto- 

 zoologists in the world, and his contributions to this branch of 

 knowledge will be much missed. The other two were mainly 

 occupied with Embryology, Dr. R. Assheton, F.R.S., and J, W. 

 Jenkinson. The latter met his death on the battlefield in 

 Gallipoli and one of his papers was published in the period now 

 under review. 



Protozoa. — Dobell and Jameson have studied " The Chromo- 

 some Cycle in Coccidia and Gregarines " (Proc. Roy. Soc. B. 

 610, August 191 5) using as their main types Aggregata eberthi 

 and Diplocystis schneideri. They point out that the formation 

 and arrangement of the chromosomes are much more constant 

 than is generally supposed. Trypanosomes do not appear to 

 divide at all readily in the rat, but Coles has shown in his note 

 " Multiplication Forms of Trypanosoma lewisim. the Body of the 

 Rat " {Parasitology, September 191 5) that equal and unequal 

 binary fission does occur in young rats. " Experiments in 

 Trypsofrol Treatment of Trypanosomiasis (7". brucei) in Guinea 

 Pigs and of Piroplasmosis in Dogs" are recorded by Nuttall and 

 Hindle {Parasitology, September 191 5). 



Invertebrata. — Haswell has added to his previous work on the 

 Platyhelminthes a description of a new form in " Studies on the 

 Turbellaria III Didymorchis " {Quart. Jour. Micro. Sci. vol. Ixi 

 pt. 2). In the same journal Helt writes " On a New Species 

 of Pentastomid from a N. African Snake {Zamenis ravigieri)." 



