270 Mayow 



that the indignant spleen could scarcely but burst 

 itself with laughter. 



That my views as to the function of the spleen 

 may be understood, I must repeat here what has 

 already been stated, viz., that it is probable that for 

 sustaining animal life it is necessary that the animal 

 spirits, i.e.^ nitro-aSrial particles, should traverse the 

 brain, or at all events the cerebellum, in continuous 

 series, and that that is the reason why on the suppres- 

 sion of the respiration or on the interruption even for 

 an instant of the motion of the heart, the higher 

 animals at once die. 



If this is granted, it follows that the nitro-aerial 

 particles must be perpetually carried away again by 

 certain vessels ; and, mdeed, we may believe that the 

 nerves dedicated to the natural motions, and also 

 those belonging to the viscera, serve to carry away 

 the animal spirits from the cerebellum. But as for 

 natural functions, particularly for the digestion of 

 food, there is need now of more and now of less 

 afflux of nitro-aerial spirits ; while the nitro-aerial 

 particles pass through the cerebellum in a nearly 

 uniform flow : it is, hence, necessary that the super- 

 abundant nitro-aerial particles, those, namely, which 

 are not required for natural functions, should be con- 

 ducted elsewhere, and it is probable that the spleen is 

 formed in order that these superabundant nitro-aerial 

 particles should by means of it be properly mixed 

 with the mass of the blood. For these nitro-aerial 

 particles being discharged by the splenetic nerves 

 into the spleen are by its means, being diffused 

 through its parenchyma, most intimately mixed 

 with the mass of the blood : whence it comes about 

 that an effervescence sufficiently intense but yet not 

 too impetuous is excited by the nitro-aerial particles 



