ZOOLOGICAL POSITION OF THE ALBINO RAT. 267 



Von Fischer ('69) in a catalogue of the mammals of the St. 

 Petersburg Government, makes the following statement : 



" Die Wanderratte, Mus dcciunainis Pall, (russisch Kryssa- 

 Kryssa heist eigentlich Mus rattus, diese art ist bekannt unter 

 dem namen Passjuck) kommt ueberall massenhaft vor in alien 

 Farben ; schwartz, schmutziggrau bis rostgelb, weissgescheckt 

 und auch ganz weiss. " Die Hausratte, Mus rattns L., habe ich 

 nie gefangen, weshalb ich annehmen zu durfen glaube, dass diesse 

 Ratte hier auch nicht' vorkommt." 



Von Fischer ('74) used a white Mns norvegicns in his experi- 

 ments on the production of hybrids. Later Crampe ('85) also 

 used a white Mus noruegicus in experiments of the same nature. 



Haacke ('95) and Bateson ('03) studied the crosses between 

 the white Mns norvegicus and the common brown rat. None 

 of the authors, however, describe in detail the white forms which 

 they employed. 



Despite the general belief to the contrary, there are many re- 

 ports in recent literature indicating that groups of Mus rattttsa.ro. 

 still to be found in a number of localities, both in Europe and the 

 United States. 



In the United States, Mus rattns is reported from Texas, Florida 

 and other southern states, and also from Iowa. Rhoads ('03) 

 reports a number of new localities in the States of Pennsylvania 

 and New Jersey. It has been learned through Director Dr. 

 Seitz that in Germany the black rat is present in large numbers 

 in the buildings connected with the zoological garden in Frank- 

 furt a/m. 



It may be interesting to note that the occurrence of white rats 

 in a wild state has been reported from two localities in Iowa, by 

 students working in the neurological laboratory at the University 

 of Chicago. There are no means of determining, however, 

 whether these were albinos of the black or brown rat. From this 

 review it is evident, therefore, that there are, or have been, at least 

 two forms of albino rats. 



Since 1893 a colony of albino rats has been maintained in the 

 neurological laboratory at the University of Chicago, and in 1906 

 a similar colony was established at the Wistar Institute of Anat- 

 omy at Philadelphia. 



