Raymond Pearl 
17 
fairly numerous, so it was only possible to extract full data on sex, stature, body- 
weight and brain-weight for 365 males and 241 females. This material I have 
referred to in this paper as the "short " Bavarian series. For determining the 
correlation between brain-weight and age I was able to extract 529 male and 323 
female records from Bischoff's tables. This larger group I have called the "long" 
Bavarian series. The brains were weighed in the fresh condition, soon after removal 
and with the membranes. Nearly all the individuals had died in hospitals and 
a considerable number of them were convicts. Practically all were members of the 
middle and lower classes of society. The causes of death for this and Marchand's 
series were very varied, including a wide range of diseases and accidents, so that 
the material is not vitiated by the great preponderance of some one cause of death 
which might have a specific effect on brain-weight. The great majority of the 
individuals included in Bischoff's series were Bavarians. 
The Swedish data used were collected by Retzius*. The source of the material 
was in the main the autopsies at the great Sabbatsberg Krankenhaus in Stockholm, 
although some of the returns were from autopsies at the Maria Krankenhaus. This 
series of brain-weights is undoubtedly one of the best which has ever been made 
with reference to accuracy in the individual weighings and uniformity in the 
conditions and method of weighing. It is only to be regretted that the series is 
not more extensive. Regarding the racial homogeneity of the material Retzius 
says (loc. cit. p. 55): "ich iiberzeugte mich aber in den allermeisten Fallen davon, 
dass sie eine echt schwedishe Herkunft anzeigten." The method of weighing 
was as follows (loc. cit. p. 55) : " Die Gehirne wurden ohne Abnahme der weichen 
Hirnhaute, in der Regel kurz nach der Herausnahme, d. h. nur nach dem Verlust 
einer dabei stets ausfliessenden geringen Menge Blut und Cerebrospinal fliissigkeit, 
direct auf die Waageschale gelegt." The series as published by Retzius gives the 
weights of 450 male brains, and 250 female. In addition to brain-weight, age, 
stature, and cause of death are recorded. After throwing out individuals incom- 
pletely recorded, and those falling outside the age limits 20 — 80, there was left 
available for this study 416 male records and 233 female. 
Matiegkaf has furnished some very valuable data for the student of brain- 
weight. His material came from the autopsies at two institutions in Prague, the 
Institut fiir gerichtliche Medizin, and the Pathologisch-Anatomische Institut. The 
series from the former source is the larger and more complete, and is the only one 
which is used in the present discussion. This includes the brain-weights of 
372 males and 197 females, together with records of age, stature, skull-length and 
skull-breadth. The individuals were all adults between the ages of 20 and 80. 
The great majority of them were Czechs. The method of weighing the brain 
* Ketzius, A.: " Ueber das Hirngewicht der Schweden," Biol. TJntersuchunyen, N. F. Bd. ix., 
Cap. IV. pp. 61—68, 1900. 
+ Matiegka, H.: " Uber das Hirngewicht, die Schadelkapacitat uud die Kopfform, sowie deren 
Beziehungen zur psychischen Thatigkeit des Mensclien," Sitzber. des kVm. hdhiiiisclien GeseHscIi. d. 
Wissensch. Blathem.-Naturwiss. Classe, Jahrg. 1902, No. xx. pp. 1 — 75. 
Biometrika iv 3 
