The authors of the above paper call into question recent evidence on the properties of selfinterstitials, I, in Ge [Cowern et al., Phys. Rev. Lett. 110, 155501 (2013)]. We show that this judgment stems from invalid model assumptions during analysis of data on B marker-layer diffusion during proton irradiation, and that a corrected analysis fully supports the reported evidence. As previously stated, I-mediated self-diffusion in Ge exhibits two distinct regimes of temperature, T: high-T, dominated by amorphous-like mono-interstitial clusters—i-morphs—with self-diffusion entropy% 30k, and low-T, where transport is dominated by simple self-interstitials. In a transitional range centered on 475 C both mechanisms contribute. The experimental I migration energy of 1.8460. 26 eV reported by the Münster group based on measurements of self-diffusion during irradiation at 550 C< T< 680 C further establishes our proposed i-morph mechanism. VC 2015 AIP Publishing LLC.[http://dx. doi. org/10.1063/1.4929762]A recent Applied Physics Review has discussed selfdiffusion and B diffusion during irradiation at high temperature. 1 Unfortunately, erroneous assumptions in B diffusion data analysis led the authors mistakenly to critique recent work by us that identified two forms of self-interstitial in Ge. 2 Here, we show that their work when correctly interpreted confirms our conclusions. In the following discussion, CX and DX represent the concentration and diffusivity of species X, Ef X and Em X (Sf X and Sm X) its formation and migration energies (entropies), respectively, and DSD X ¼DXCX eq/C0, where C0 is the lattice density, is the contribution of X to equilibrium self …