580 SUMMARY OF CURRENT RESEARCHES RELATING TO 



he advanced in 1875 that the lungs of Amphibians are derivatives of the 

 posterior branchial pouches. 



In the Ammocoete there is a progressive degeneration of the posterior 

 branchial pouches; they become small gill-less caeca of the gut, and some- 

 times entirely disappear, leaving the sixth pair exceedingly like the 

 rudiments of the lungs in Amphibians. In recent Euichthyes no such 

 form of degeneration is seen, for the branchial pouches from the second 

 onwards are simple clefts whose only change is that they close and dis- 

 appear. But in the larvae of anurous Amphibians distinct branchial 

 pouches re-appear, and just behind the last pair lie the primordia of the 

 lungs, which look exactly like the rudimentary posterior branchial 

 pouches of the lamprey. By these and other arguments Goette supports 

 his conclusion that the first true lungs appeared in the Enterobranchia, 

 and directly from modified branchial pouches. 



Hyperdactylism.* — E. Ballowitz points out that there are two rival 

 interpretations of the occurrence of supernumerary digits. Thus Darwin 

 interpreted it as atavistic, as a reversion to an unknown polydactylous 

 ancestor, while others have interpreted it as teratological, due to a 

 splitting of the normally single primordium of a finger or toe, the 

 splitting being traced to irregularities in the amnion. The amnion 

 may be too small, it may show thickenings or fusions, folds and strands. 

 Ahlfeld found an amniotic thread on the splitting region of a double 

 thumb. Ballowitz has studied the musculature and skeletal parts of four 

 fine cases of hyperdactylism in man, and his conclusion is that the state 

 of the muscles, tendons, and bones supports the splitting theory, and is 

 wholly against the atavistic theory. 



Evolution of Mammals.f — Marcellin Boule replies to M. Deperet's 

 recent attack on palseontological methods. He says that the . critic has 

 misrepresented the facts, e.g. in supposing that palaeontologists now 

 believe that the modern horse is the product of a direct filiation 

 beginning with Palmotherium, and passing through Anchitherium 

 and Hipparion. On the contrary, this view was abandoned by most 

 palaeontologists almost a quarter of a century ago ; Palceotherium and 

 Hipparion are not regarded as direct ancestors of Equus, but as the 

 dwindling terminations of two lateral branches. 



Is Rabies Transmissible from Mother to Offspring ? % — D. Konradi 

 points out that placental- transmission has been securely proved in 

 anthrax, pneumonia, typhus, pyogenic coccus, recurrent fever, variola, 

 malleus, syphilis, and tuberculosis. He has experimented with the virus 

 of rabies introduced into pregnant guinea-pigs and rabbits, and he has 

 satisfied himself that there is transmission from the mother to the foetus, 

 with some attenuation in the process. 



Pancreatic Bladder in Cat.§— W. S. Miller has found four cases of 

 a pancreatic bladder in the domestic cat. In the last discovered case 

 the pancreatic bladder occupies a special depression to the left of the 

 gall bladder in the quadrate lobe ; it is separated by a very thin double- 



* Verh. Anat. Ges., 1904; Anat. Anzeig., xxv., Erganzungslu-ft, fpp. 124-35 

 3 fi gs). t Comptes Rendus, cxl. (1905) pp. 1662-4. 



X Centralbl. Bakt. Parasitenk., xxxviii. (1905) pp. 60-5. 

 § Anat. Anzeig., xxvii. (1905) pp. 119-20 (1 tig.). 



