RECENT ADVANCES IN SCIENCE 563 



Child has continued his studies on the phenomena of 

 experimental reproduction in " Studies on the Dynamics of 

 Morphogenesis and Inheritance in Experimental Reproduction. 

 X, Head-frequency in Planar ai dorotocephalia in Relation to 

 Age, Nutrition, and Motor Activity " {Jour. Exp. ZooL, vol. xxx, 

 no. 3, April 1920). It is found that the frequency with which 

 heads are produced in regenerating pieces is lower in pieces of 

 younger animals, in pieces of starved animals, and in pieces 

 that are not frequently stimulated to activity after the operation. 

 The range of head-forms is the same in all cases, showing that 

 these stimuli are simply quantitative, and not qualitative, in 

 their effect. 



Other papers include : 



Ciurea, " Sur la Source d'Infection du Chien et du Chat avec I'Echinochas- 

 mus perfoliatus (v. Ratz) et la Question d'Infection de I'Homme avec les 

 Diatomes de la Famille des Echinostomides " [Jour. Parasit., vol. vi, no. 4, 

 June 1920) ; Cobb, " A Newly-discovered Parasitic Nematode {Tylenchus 

 mahogani, n. sp.) connected with a Disease of the Mahogany Tree " [ibid.) ; 

 Duncan, "On Acari from the Lungs of Macacus rhesus" {Jour. Roy. Micro. 

 Soc, pt. 2, June 1920) ; Faust, " Criteria for the Differentiation of Schistome 

 Larvae " [Jour. Parasit., vol. vi, no. 4, June 1920) ; Kepner and Helvestine, 

 " Pha.Tyn-x.oi Microstoma caudatum" [Jour. Morph. , vol. ^3, no. 2, March 1920); 

 Kobayashi, " On a New Species of Rhabitoid Worms found in the Human 

 Intestines " (Jour. Parasit., vol. vi, no. 3) ; Magath, " Leuchloridium 

 problematicum, n. sp." [ibid.) ; Schwarz, " The Biological Relationships of 

 Ascarids " {ibid.) ; Scott, " Notes and Experiments on Sarcosystis tenella 

 Raillet " {ibid., vol. vi, no, 4, June 1920) ; van Cleave, " Notes on the Life 

 Cycle of Two Species of Acanthocephalia from Freshwater Fishes" {ibid.). 

 Yokogawa and Susumu Suyemori, " Observations on Abnormal Courses of 

 Infection of Paragonimus ringeri " {ibid.) ; and Yoshida, " On the Resistance 

 of Ascaris Eggs " {ibid., vol. vi, no. 3, March 1920) ; Tannreuther, " The 

 Development of Asplanchnia ebbesbornii (Rotifer) " {Jour. Morph., vol. 33, 

 no, 2, March 1920), 



" The Development of the Starfish Crossaster papposus, 

 Miiller and Troschel," is described in considerable detail by 

 Gemmill {Quart. Jour. Micro. Set., vol. Ixiv, no. 2, Jan. 1920). 

 There is a decided resemblance between the development of 

 this species and that of Solaster endeca, which has been described 

 previously by the same author. The archenteron early exhibits 

 three divisions, of which the anterior gives rise to the cavity 

 of the praeoral lobe, hydroporic canal, hydrocoel, epigastric 

 coelom, axial sinus, stone canal, axial organ, internal oral 

 perihsemal ring, and oral haemal ring ; the middle to all portions 

 of the digestive cavity of the adult ; and the posterior to the 

 hypogastric coelom, the pharangeal or perioral coelom, the 

 external oral perihaemal ring, the " genital rachis," and the 

 aboral perihaemal sinus. The larva is not a feeding form, and 

 consequently has no mouth, CESophagus, or anus. 



