^-j^Q Mammalia. 



peral which it inhabits, and thus escape pursuit. The carapace also reduces the 

 evaporation, an important factor in a semiarid region. The armour is probably 

 phylogenetically older than the present arid environment of the armadillo, so 

 that, in choosing its habitat, the species has selected an unpreempted food area 

 with shelter from enemies. The animals are chiefly insectivorous, extremely sen- 

 sitive to cold, and rely chiefly upon their sense of smell, — sight and hearing 

 being but poorly developed. 



The well-known polyembryonic condition is discussed and interpreted in 

 the light of previous work by Newman and Patterson. A specific protozoon 

 parasite has recently been found in all the eggs, and it is suggested that this 

 parasite, by lowering the vitality of the egg, leads to a condition of senescence 

 which expresses itself in reproduction by budding. The quadruplets which are 

 normally produced in a single chorion arise by the formation of primary bud 

 primordia from a single original egg. 



The quadruplets are invariably of the same sex, and cytological studies 

 shew the presence of an accessory sex chromosome, the diploid female number 

 of chromosomes being 32 and the haploid 16; the male diploid 31, producing 

 tvvo kinds of sperms having respectively 15 and 16 chromosomes. This is in 

 strong Support of the chromosome theory of sex determination. Patterson has 

 also found one of the primary bud primordia frequently dividing in advance of 

 the other. The writer therefore concludes that "if sex is capable of being in- 

 fluenced b}^ metabolic inequalities of any sort, these should be opportunity here 

 for the Operation of such influence. Yet there is not a single instance in which there 

 is any diversit}^ of sex within a set of fetuses derived from a single germ cell". 



The problem of inheritance in these polyembryonic offspring is one of pe- 

 culiar interest, and it is found that various peculiarities of certain scutes in the 

 armour may be inherited by some of the quadruplets and not by others. Thus 

 there appears to be segregation of some material substances during the cleavage 

 of the egg. These peculiarities of the scutes appear to be inherited in Mendelian 

 fashion and not as blends. If this is the case, one must conclude that Mendelian 

 inheritance is not necessarily conditioned by segregation of factors only at the 

 time of chromosome reduction. [Similar results in Bacteria and elsewhere point 

 to the same conclusion.J Gates (London). 



274) Tome, 0. (Dorpat, Zool. Inst.), Über das knorpelige Accessoriura 

 der Vespertilionidenhand. In: Morpholog. Jahrbuch, Bd. 45, Heft 3, S. 431 

 bis 440, 1913. 



Verf. macht Mitteilungen über Vorkommen, Lage, Form und Variabilität des 

 Accessoriums, eines kleinen Knorpelstäbcheus am Rande der Flughaut von vielen 

 Chiropteren, das annähernd parallel dem fünften Finger, an dessen ulnarem Rande 

 liegt, und schildert dann die Beziehungen, die es zu benachbarten Teilen der 

 Flughaut hat. Mit den Muskelsehnen des fünften Fingers hat das Accessorium 

 nichts zu tun, wohl aber tritt es in Beziehung zu gewissen Bindegewebszügen, 

 die die Flughaut-„aderung" darstellen. Durch Vergleich mit dieser Aderung bei 

 Chiropteren, die das Knorpelstäbchen nicht besitzen, kommt Verf. zu der An- 

 sicht, daß das Accessorium eine bestimmte Funktion haben muß. Seine Be- 

 wegungen können in anderer Richtung erfolgen, als die Bewegungen des Finger- 

 gliedes, wodurch der Teil der Flughaut, der sich zwischen dem fünften Finger 

 und Körper befindet, eine gewisse Selbständigkeit erhält. 



H. B ö k e r (Freiburg i. Br.). 

 Hierzu: Nr. 150, 156 — lö'J, 175—177, 183, 195, '212, 220, 222, 223, 265, 266. 



