430 PKOF. G. ELLIOT SMITH OX THE 



The area C is a little bifoliate iiodule placed iijion the caudal surface lietwcen the area B 

 and the copula pyramidis which may he regarded as an area D. Unlike the area B, C is 

 freely connected "with the mesial parts by a broad band. 



The tissures which indent the mesial part, so-called "vermis,"' of the middle lobe 

 do not extend, into the lateral regions. The limiting tissures of the areas A, B, C, and D 

 arise laterally and do not extend, on to the mesial area in Tarsius. 



The anterior lobe ditfers in appearance from the other two lobes. It is broadest 

 in the middle line and gradually tapers toward the region of the entrance of the middle 

 peduncle into the cerebellum. Its surface is incised by two deep and tliree shallow 

 fissures, the former of which extend, as far as the middle peduncle. 



In the brain of Lemur, the pattern exhibited in a mesial sagittal section of the 

 cerebellum is much more complicated than that of Tarsim, but the plan is essentially 

 the same (fig. 65). It so closely resembles that of Orycteropm which I have described in 

 my memoir on the brain in the Edentata {op. cit. fig. 29, p. 362), that it is unnecessary 

 to repeat the account. In the accompanying figure I have inserted letters to represent 

 fissures homologous Avitli those similarly distioguished in Ori/cteropiis. 



The general plan of tlu^ cerebellum closely conforms to the type found in such 

 mammals as the Dog, the Anteater, and the smaller Apes. 



The floccular lobe is divided, as in all mammals, into a ventral part — the floecidus — 

 and a dorsal part — the ])araflocculus. Tlie flocculus con.sists of a little wedge-shaped 

 mass closely applied to the lateral aspect of the pons Varolii immediately in front 

 of the tuberculum acusticum and external to the trigeminal nerve. Its broad anterior 

 aspect is subdivided into folia by five or six horizontal fissures. The posterior extremity 

 of the wedge-shaped mass is connected by a long white baud with the nodulus. 



The paraflocculus consists of an ii'regular mass of folia placed on the dorso-lateral 

 aspect of the flocculus, so that in a lateral vicAV of the brain the latter is almost 

 completely hidden by it. From its lowermost part (/. e. the region nearest the flocculus) 

 a narrow stalk emerges and swells out into a plump projecting mass of folia arranged in 

 a feather-like pattern. This projecting part of tlie paraflocculus is often called the 

 " petrosal lobule" and more commonly simjdy " flocculus." It presents a similar form 

 in all Apes except the Simiidse. In Hylobates, however, the typical Primate foi'm 

 of floccular lobe is fully developed. 



The nearest approach to this type of floccular lol)c among other mammals is exhibited 

 in the Ungnlata, of which the accompanying drawing of the lateral aspect of the 

 Gazelle's cerebellum is typical (fig. QQ). 



In Tarsius the paraflocculus has been described as being directly linked by a simple 

 cortical band to the pyramid. In Lemur a vastly different state of aflairs obtains. 

 Starting from the stalk of the so-called petrosal lobule, a series of folia (and not a 

 continuous undivided band) forms a worm-like coil which curves forward, then upward 

 and horizontally backward (compare the Gazelle's cerebellum, fig. 66). The series of 

 disconnected folia then proceeds backward below the area B to the lower end of the 

 area C, and it becomes impossible to accurately sepai-ate the series of folia belonging 

 to the parafloccular (or perhaps it wovdd be more accurate to say " copu'Iar ") group 



