# The Arrangement of the Osteons and [PERSON]'s Conjecture
## 3 Results  
Osteons with typical morphological features characterized by concentric bone lamellae surrounding a Haversian canal were present in all the species examined. They showed high variability in size, including the number of bone lamellae, the diameter of the osteeons, and consequently, the perimeter and the area of the osteeons. This variability depended on the species and the bone considered and often was present in the same histological slide. The main morphological and morphometrical features of the osteeons in the species observed are reported in Table 1, where in extreme synthesis, it can be noted that the horse osteeons were more extensive than those of ruminants (cows, goats, sheep, moulfons, deer), themselves larger than those of suids (domestic pigs, wild boars), themselves larger than those of carnivores (dogs, foxes).  
Regarding the type of bone tissue, besides plexiform tissue, both irregular Haversian and dense Haversian tissue were present in all species with different extensions (Figure 1). In ascending order of greatest presence of dense Haversian tissue than irregular Haversian tissue can be listed carnivores, suids, ruminants, and horses. Moreover, dense Haversian tissue is generally larger in the wild species (deer, moulfons, wild boars, foxes) than in domestic animals.  
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & \multicolumn{4}{c}{**Osteon Measurements**} & \multicolumn{2}{c}{**Haversian Bone Tissue**} \\ \cline{2-6}  & **n** & **On.Dm** & **On.Ar** & **On.Dn** & **Irregular** & **Dense** \\ \hline Horse (_Equus caballus_) & 147 & 198.4 \(\pm\) 32.9 & 31,582.5 \(\pm\) 4386.2 & 5.1 & + & ++++ \\ \hline Cow (_Bos taurus_) & 134 & 164.7 \(\pm\) 27.3 & 19,538.0 \(\pm\) 2708.5 & 4.4 & ++ & +++ \\ \hline Deer (_Cervus elaplus_) & 43 & 135.9 \(\pm\) 18.1 & 13,613.3 \(\pm\) 2144.6 & 4.8 & ++ & +++ \\ \hline Pig (_Sus scrofa domestica_) & 103 & 138.6 \(\pm\) 41.6 & 14,721.4 \(\pm\) 1928.4 & 2.9 & +++ & ++ \\ \hline Wild boar (_Sus scrofa_) & 98 & 179.3 \(\pm\) 25.8 & 22,167.1 \(\pm\) 3319.7 & 3.9 & ++ & +++ \\ \hline Sheep (_Ovis aries_) & 170 & 128.2 \(\pm\) 33.2 & 15,182.4 \(\pm\) 2361.5 & 3.2 & ++++ & + \\ \hline Goat (_Capra hircus_) & 162 & 124.7 \(\pm\) 24.5 & 14,601.3 \(\pm\) 2173.8 & 3.8 & +++ & + \\ \hline Mouflon (_Ovis musimon_) & 109 & 156.6 \(\pm\) 26.4 & 18,039.2 \(\pm\) 2549.3 & 4.1 & +++ & ++ \\ \hline Fox (_Vulpes valpes_) & 56 & 139.4 \(\pm\) 37.0 & 15,496.7 \(\pm\) 1838.2 & 2.9 & +++ & ++ \\ \hline Dog (_Canis familiaris_) & 74 & 125.2 \(\pm\) 22.8 & 14,083.2 \(\pm\) 2071.6 & 2.4 & ++++ & + \\ \hline \hline \end{tabular}  
* The osteon diameter (On.Dm) and osteon area (On.Ar) are the mean values of one hundred measurements (expressed, respectively, in \(\mu\) and \(\mu^{2}\)); n, number of osteeons measured; \(\pm\)standard deviation. Qualitative observations express the frequency of the irregular Haversian and dense Haversian tissues. From + to ++++ are indicated the growing amount of two types of Haversian bone tissue.  
\end{table}
Table 1: Histomorphometrical data of the Haversian bone tissue in different species 1.  
The main aim of this work was to observe different arrangements of the osteons. It varied from a case of random dispersion, where the osteons were few and far from each other, to a condition where the osteons were numerous and cramped. The scenario of the osteon arrangement is often complex because osteons with different sizes can be present in the same field, which aggravates the possibility of easily recognizing the schemes of the osteon layout. The arrangement typical of the irregular Haversian tissue could be better defined as the tissue where the osteons are not in contact with each other and then their cement line, that is the periphery of each osteon, does not even have a single point in common with the others (Figure 1b). Therefore, in this tissue type, the interosteonal area is very wide.