326 Analysis of Scientific Books. 



5. Enaerogenoa. Embryo ex ovo in oviducto impregnate, absque in- 



cubatione evolutus. 



6. Amphibigenoa. Embryo ex ovo in ovario formato, instructus pulmoni- 



bus et branchiis nurlis evolutus in aqua. 



7. Enhydrogenoa. Embryo ex ovo in ovario formato, branchiis operculo 



tectis instructus evolutus in aqua. 

 S. Metamorphogenoa. Embryo ex ovo in ovario formato, subjectus meta- 

 morphosi, stigmatibus respirans. 



9. Monogenoa. Embryo ex ovo a mare monorchide impregnate, branchiis 



instructus. 



10. Hermaphoditogenoa. Embryo ex ovo liermaphroditi duplicis. 

 1 ) . Autogenoa. Embryo ex ovo liermaphroditi unici. 



12. Cryptogenoa. Embryones quorum primordia ignota. 



IV. Philosophical Transactions of the Royal Society of London, 

 for the Year MDCCCXXIII. Part I. 



This part of the Philosophical Transactions contains twelve 

 papers, illustrated by twenty engravings, the greater part of 

 which are very creditably executed. The following are the titles 

 and contents of the communications. 



1. The Croonian Lecture. Microscopical Observations on the Suspen- 

 sion of the Muscular Motions of the Vibrio Tritici. By Francis 

 Bauer, Esq., F.R.S. 



The animalcule described in this paper, is the cause of that disease 

 in wheat, called by farmers ear~cockles or purples. The diseased 

 grains include a white globular matter, which, when put into water 

 displays, in the field of the microscope, hundreds of minute worms 

 in lively motion. As the water evaporates they dry up and are 

 motionless, but become as lively as ever, when re-moistened, and 

 this after a period of more than six years. By some ingenious 

 experiments Mr. Bauer shows that the eggs of these vermi- 

 culi are conveyed into the plant by the circulating sap, and he 

 succeeded in obtaining infected plants by inoculating healthy 

 grains of wheat with portions of the vermicular globules. For the 

 dimensions, aspects, and habits, of these worms we refer our 

 readers to the author s paper, and to the two beautiful plates 

 which illustrate it. 



2. On Metallic Titanium. By W. H. Wollaston, M.D., V.P.R.S. 



Certain small cubes occasionally observed in iron slag, had 

 generally been regarded as pyritical, but upon minute inspection 

 Dr. Wollaston observed, that neither their colour, crystallization, 

 nor hardness, were those of pyrites. These crystals, purified from 



