300 REICHERT AND BROWN— PRELIMINARY REPORT UPON [April 24, 



baboon thus far examined, nor did they show the characters of the 

 genus Papio. They were identified by their crystahographic char- 

 acters as belonging to the cats (genus Fclis) but not to any species 

 that we had examined up to that time. Inquiry at the Zoological 

 Garden from which the blood was received showed that the animal 

 recorded as being subjected to a post-nwrtcm examination on the 

 date when the blood was collected was a species of the genus Felis, 

 but not one of which we had previously examined the blood. Other 

 similar cases of incorrect labelling of specimens were detected, in 

 which the wrongly labelled blood was one that had been examined 

 and the species known from other specimens. 



2. Specificity in the Crystals of a Genus. — The crystals of the 

 different species of a genus, when they are favorably developed for 

 good measurement, can usually be distinguished from each other by 

 definite differences of angle, etc. ; while preserving their isomorphous 

 character as belonging to a definite genus. In cases where, on 

 account of difficulty of measurement, the differences cannot be given 

 a quantitative value, variations in the habit of the crystals and in 

 their mode of growth will often show specific differences. 



3. The Occurrence of Several Types of Crystals of Oxyhemo^ 

 globin in Many Species. — In some species the oxyhemoglobin is 

 dimorphous (crystallizing in two systems or with two axial ratios), 

 in other cases even triinorphous. Where several types of crystal 

 occur in this way in the species of any genus, the crystals of each 

 type may be arranged in an isomorphous series. In other words, 

 certain genera are isodimorphous or isotrimorphous. 



4. The Constant Recurrence of Certain Angles, Plane or Dihe- 

 dral, in the Oxyhemoglobin, Hemoglobin and the " Methenioglo- 

 bins " of Various Species, even when these Species are Widely Sep- 

 arated Zoologically and zvhcn their Crystals Belong to Various Crys- 

 tal Systems. — This appears to indicate a common substance in hemo- 

 globins or a common structure in the various hemoglobin molecules. 



5. The Constant Recurrence of Certain Types of Tivinning in 

 the Hemoglobins, and the Prevalence of Mimosie in these Crystals. 

 — This also indicates a common structure in the various hemoglobin 

 molecules. 



