Recently Balagurusamy et al (1990, hereafter P1) considered the diffraction by (finite-size) one-dimensional quasilattices and the corresponding two-dimensional case of Penrose tilings has been considered by Baranidharan et al (1990, hereafter P2). That Penrose patterns based on aperiodic tilings do show sharp Bragg like diffraction maxima would appear to have been pointed out by Mackay (1981, 1982) although subsequently, in the context of discovery of Schechtman et al (1984), quasilattice diffraction with similar properties have been worked out by a number of authors (e.g. Levine and Steinhardt 1984; Elser 1986; Prince 1987). These authors have considered essentially infinite lattices and the case of one-dimensional Fibonacci lattice is elegantly worked out by Prince (1987). The authors of P1 and P2 have attempted to study the effect of finiteness of the lattice on the diffraction pattern, particularly using numerical cum computer calculation with unit scattering power for the scatterers. It is most surprising that the authors of both P1 and P2 have not bothered to correlate their observation, with well-known diffraction theory of effect of finiteness of size of scattering object. The effect of this is a slit function for the one-dimensional case and a circular aperture function for the two-dimensional case. The observed data are to be interpreted or correlated in terms of the modulation of the FT of infinite lattice by the appropriate window function which, as is well-known, yields maxima and minima close to the origin of the reciprocal space. In particular, for the two-dimensional case the Bessel function exhibits maxima and minima of rapidly decreasing amplitudes and also with progressively increasing spacings between maxima. These are observable in the various figures in P2. In as much as they have used unit scattering power and delta function-like behaviour, the oscillation may not be construed to dampen out in the transform space (k-space). The fluctuation observed for N < 50, and also for large value of N for weak peaks (with probably only exception of strong peak away from the origin) are most likely to originate from the above effect. Even for N = 1000 in the two-dimensional case, allowing for weighted average of the two rhombuses would yield, for the radius of the window circle, a value of the order of 10(d) where (d) is 1 + 1/'c 2 = 3 ~. If an estimate is made of the realistic experimental conditions where they are expected to be applicable, grain sizes of quasi crystals are of the order of microns and if the minimal spacings is of the order of atomic dimensions micro domain would correspond to the order of 104 ,~, and the effect, including peak shifts that are discussed will be inapplicable. In has been shown by Prince (1987) for the case of one-dimensional Fibonacci lattice, apart from the delta function-like maxima given by ( 6 ( k I/a,,,)) where l, m